136 files changed, 136 insertions, 136 deletions

diff --git a/Tachometer.c b/Tachometer.c
index f87791e6..b90929dc 100644
--- a/Tachometer.c
+++ b/Tachometer.c
@@ -7,7 +7,7 @@
  * Cleaned up and simplified by Eric S. Raymond, December 2004.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <X11/IntrinsicP.h>
 #include <X11/StringDefs.h>
diff --git a/Tachometer.h b/Tachometer.h
index a80cd4ff..16139c1f 100644
--- a/Tachometer.h
+++ b/Tachometer.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_TACHOMETER_H_
 #define _GPSD_TACHOMETER_H_
diff --git a/TachometerP.h b/TachometerP.h
index 401c3cfa..2fea3203 100644
--- a/TachometerP.h
+++ b/TachometerP.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_TACHOMETERP_H_
 #define _GPSD_TACHOMETERP_H_
diff --git a/bits.c b/bits.c
index 2f7739cc..6044a8f6 100644
--- a/bits.c
+++ b/bits.c
@@ -1,7 +1,7 @@
 /* bits.c - bitfield extraction code
  *
  * This file is Copyright (c)2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * Bitfield extraction functions.  In each, start is a bit index  - not
  * a byte index - and width is a bit width.  The width is bounded above by
diff --git a/bits.h b/bits.h
index c8f88488..66b17d10 100644
--- a/bits.h
+++ b/bits.h
@@ -9,7 +9,7 @@
  * Both 32- and 64-bit systems with gcc are OK with this set.
  *
  * This file is Copyright (c)2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_BITS_H_
 #define _GPSD_BITS_H_
diff --git a/crc24q.c b/crc24q.c
index 34b2dd46..5c11c054 100644
--- a/crc24q.c
+++ b/crc24q.c
@@ -24,7 +24,7 @@
  * requires this.
  *
  * This file is Copyright (c) 2008,2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdbool.h>
 #include <stdio.h>
diff --git a/crc24q.h b/crc24q.h
index 8ad6f0ce..832212a9 100644
--- a/crc24q.h
+++ b/crc24q.h
@@ -1,7 +1,7 @@
 /* Interface for CRC-24Q cyclic redundancy chercksum code
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _CRC24Q_H_
 #define _CRC24Q_H_
diff --git a/dbusexport.c b/dbusexport.c
index c5d0cff5..2f9f91ed 100644
--- a/dbusexport.c
+++ b/dbusexport.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include "gpsd.h"
 #if defined(DBUS_EXPORT_ENABLE)
diff --git a/driver_ais.c b/driver_ais.c
index 5f48c595..cc60779b 100644
--- a/driver_ais.c
+++ b/driver_ais.c
@@ -13,7 +13,7 @@
  *  - IMO289 met/hydro message: Type=8, DAC=1, FI=31
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifdef __linux__
diff --git a/driver_evermore.c b/driver_evermore.c
index ed1c34b3..9d6623f7 100644
--- a/driver_evermore.c
+++ b/driver_evermore.c
@@ -121,7 +121,7 @@
  * c5 is EverMore checksum, other bytes are fixed
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/driver_garmin.c b/driver_garmin.c
index 3b17a84a..2230d2ed 100644
--- a/driver_garmin.c
+++ b/driver_garmin.c
@@ -74,7 +74,7 @@
  *	?? Add probe function for Serial Binary to start PVT output.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #define __USE_POSIX199309 1
diff --git a/driver_garmin_txt.c b/driver_garmin_txt.c
index e8e878a2..f452c612 100644
--- a/driver_garmin_txt.c
+++ b/driver_garmin_txt.c
@@ -24,7 +24,7 @@
  *      satellite information
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/driver_geostar.c b/driver_geostar.c
index 5866ddce..f873b4cc 100644
--- a/driver_geostar.c
+++ b/driver_geostar.c
@@ -7,7 +7,7 @@
  * By Viktar Palstsiuk, viktar.palstsiuk@promwad.com
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <sys/time.h>		/* for select() */
diff --git a/driver_italk.c b/driver_italk.c
index ce949e11..fe7fa107 100644
--- a/driver_italk.c
+++ b/driver_italk.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * Driver for the iTalk binary protocol used by FasTrax
  *
diff --git a/driver_italk.h b/driver_italk.h
index b0ed9f5a..bfeb1b71 100644
--- a/driver_italk.h
+++ b/driver_italk.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_ITALK_H_
 #define _GPSD_ITALK_H_
diff --git a/driver_navcom.c b/driver_navcom.c
index 6f1aaaae..860ec43a 100644
--- a/driver_navcom.c
+++ b/driver_navcom.c
@@ -32,7 +32,7 @@
  * unhappy things will occur on the next rollover.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/driver_nmea0183.c b/driver_nmea0183.c
index 94cf4dc3..eb3d881c 100644
--- a/driver_nmea0183.c
+++ b/driver_nmea0183.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* for vsnprintf() FreeBSD wants __ISO_C_VISIBLE >= 1999 */
diff --git a/driver_nmea2000.c b/driver_nmea2000.c
index 7abf120e..38b077e5 100644
--- a/driver_nmea2000.c
+++ b/driver_nmea2000.c
@@ -2,7 +2,7 @@
  * NMEA2000 over CAN.
  *
  * This file is Copyright (c) 2012 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* need this for strnlen() and struct ifreq */
diff --git a/driver_nmea2000.h b/driver_nmea2000.h
index fa498ed9..d87f04df 100644
--- a/driver_nmea2000.h
+++ b/driver_nmea2000.h
@@ -4,7 +4,7 @@
  * The entry points for driver_nmea2000
  *
  * This file is Copyright (c) 2012 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef _DRIVER_NMEA2000_H_
diff --git a/driver_oncore.c b/driver_oncore.c
index 0063d6a9..acdf8f15 100644
--- a/driver_oncore.c
+++ b/driver_oncore.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdbool.h>
diff --git a/driver_proto.c b/driver_proto.c
index 408dfdb3..df136e86 100644
--- a/driver_proto.c
+++ b/driver_proto.c
@@ -33,7 +33,7 @@
  * packet_states.h
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdbool.h>
diff --git a/driver_rtcm2.c b/driver_rtcm2.c
index 2dbc0ba0..52a04416 100644
--- a/driver_rtcm2.c
+++ b/driver_rtcm2.c
@@ -52,7 +52,7 @@ message types 4, 5, 6, 7, and 13 has not been checked. Message types
 60-63 are not yet supported.
 
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 
 *****************************************************************************/
 
diff --git a/driver_rtcm3.c b/driver_rtcm3.c
index 7edd69aa..91e6ab5b 100644
--- a/driver_rtcm3.c
+++ b/driver_rtcm3.c
@@ -34,7 +34,7 @@ has been observed to correctly analyze a message with a nonempty Receiver
 field.
 
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 
 *****************************************************************************/
 
diff --git a/driver_sirf.c b/driver_sirf.c
index 25304913..a43d79cf 100644
--- a/driver_sirf.c
+++ b/driver_sirf.c
@@ -32,7 +32,7 @@
  * the manual advises; this does not fix the problem.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/driver_skytraq.c b/driver_skytraq.c
index 3c8f3ad8..2861d39b 100644
--- a/driver_skytraq.c
+++ b/driver_skytraq.c
@@ -2,7 +2,7 @@
  * This is the gpsd driver for Skytraq GPSes operating in binary mode.
  *
  * This file is Copyright (c) 2016 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/driver_superstar2.c b/driver_superstar2.c
index 53b8ad49..79e186f1 100644
--- a/driver_superstar2.c
+++ b/driver_superstar2.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdbool.h>
diff --git a/driver_superstar2.h b/driver_superstar2.h
index 30416bbf..c39d8523 100644
--- a/driver_superstar2.h
+++ b/driver_superstar2.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_SUPERSTAR2_H_
 #define _GPSD_SUPERSTAR2_H_
diff --git a/driver_tsip.c b/driver_tsip.c
index f3801c46..a08f10c7 100644
--- a/driver_tsip.c
+++ b/driver_tsip.c
@@ -10,7 +10,7 @@
  * unhappy things will occur on the next rollover.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifdef __linux__
diff --git a/driver_ubx.c b/driver_ubx.c
index 20136611..f62fa3ab 100644
--- a/driver_ubx.c
+++ b/driver_ubx.c
@@ -15,7 +15,7 @@
  * the sats, one presumes) is 0sec; for the u-blox 6 it's 15sec.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/driver_zodiac.c b/driver_zodiac.c
index 11a53ed8..22fdc80d 100644
--- a/driver_zodiac.c
+++ b/driver_zodiac.c
@@ -7,7 +7,7 @@
  * unhappy things will occur on the next rollover.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifdef __linux__
diff --git a/drivers.c b/drivers.c
index f1057ca8..eda1fd61 100644
--- a/drivers.c
+++ b/drivers.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* for vsnprintf() FreeBSD wants __ISO_C_VISIBLE >= 1999 */
diff --git a/geoid.c b/geoid.c
index 4a6a39a7..cbcec2f0 100644
--- a/geoid.c
+++ b/geoid.c
@@ -5,7 +5,7 @@
  * ECEF conversion by Rob Janssen.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <math.h>
diff --git a/gps.h b/gps.h
index 478921fc..8784a97b 100644
--- a/gps.h
+++ b/gps.h
@@ -1,7 +1,7 @@
 /* gps.h -- interface of the libgps library */
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_GPS_H_
 #define _GPSD_GPS_H_
diff --git a/gps.xml b/gps.xml
index e9cd9fd1..6d59277f 100644
--- a/gps.xml
+++ b/gps.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gps2udp.c b/gps2udp.c
index 2c1ab765..8cfb14b9 100644
--- a/gps2udp.c
+++ b/gps2udp.c
@@ -8,7 +8,7 @@
  * Date:   2013-03-01
  *
  * This file is Copyright (c) 2013 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/gps2udp.xml b/gps2udp.xml
index 4df652e9..b222b138 100644
--- a/gps2udp.xml
+++ b/gps2udp.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2013 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gps_json.h b/gps_json.h
index 1d4cf586..9d97304c 100644
--- a/gps_json.h
+++ b/gps_json.h
@@ -2,7 +2,7 @@
  *
  * By Eric S. Raymond, 2009
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include "json.h"
diff --git a/gpscap.ini b/gpscap.ini
index c8b31ebd..6d1aa90d 100644
--- a/gpscap.ini
+++ b/gpscap.ini
@@ -1,7 +1,7 @@
 # GPS capability description file
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # Our apologies to all Unix hackers in advance for the grubby .INI syntax,
 # we're using it because the format has good cross-Unix support in Python.
diff --git a/gpscap.py b/gpscap.py
index 188a8393..28ce0f69 100644
--- a/gpscap.py
+++ b/gpscap.py
@@ -2,7 +2,7 @@
 gpscap - GPS/AIS capability dictionary class.
 
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 """
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
 # Preserve this property!
diff --git a/gpscat b/gpscat
index f100c495..01199f8b 100755
--- a/gpscat
+++ b/gpscat
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # Display GPS output.  Hexify it if necessary.
 #
diff --git a/gpscat.xml b/gpscat.xml
index 70e0850d..a22b6a84 100644
--- a/gpscat.xml
+++ b/gpscat.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsclient.c b/gpsclient.c
index 7999c2e5..bd71ce05 100644
--- a/gpsclient.c
+++ b/gpsclient.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * Python binding for selected libgps library functions
  */
diff --git a/gpsctl.c b/gpsctl.c
index a8769eda..9a425f16 100644
--- a/gpsctl.c
+++ b/gpsctl.c
@@ -1,7 +1,7 @@
 /* gpsctl.c -- tweak the control settings on a GPS
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/gpsctl.xml b/gpsctl.xml
index 4c3c4d33..b0f9f6c0 100644
--- a/gpsctl.xml
+++ b/gpsctl.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsd.c b/gpsd.c
index 8ec8b571..011b445d 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -3,7 +3,7 @@
  * select loop, and user command handling lives here.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifdef __linux__
diff --git a/gpsd.h b/gpsd.h
index a6e60ef5..2bd5f4c0 100644
--- a/gpsd.h
+++ b/gpsd.h
@@ -1,7 +1,7 @@
 /* gpsd.h -- fundamental types and structures for the gpsd library
  *
  * This file is Copyright (c) 2017 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef _GPSD_H_
diff --git a/gpsd.hotplug b/gpsd.hotplug
index 69fa00de..9f622cd1 100644
--- a/gpsd.hotplug
+++ b/gpsd.hotplug
@@ -17,7 +17,7 @@
 # work under Ubuntu.
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 
 PATH=/usr/sbin:$PATH
 export PATH
diff --git a/gpsd.rules.in b/gpsd.rules.in
index 8361a90c..dfc69fbb 100644
--- a/gpsd.rules.in
+++ b/gpsd.rules.in
@@ -1,7 +1,7 @@
 # udev rules for gpsd
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # GPSes don't have their own USB device class.  They're serial-over-USB
 # devices, so what you see is actually the ID of the serial-over-USB chip.
diff --git a/gpsd.usermap b/gpsd.usermap
index 64713c81..8a032001 100644
--- a/gpsd.usermap
+++ b/gpsd.usermap
@@ -1,7 +1,7 @@
 # Hotplug device map for GPSD
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # GPSes don't have their own USB device class.  They're serial-over-USB
 # devices, so what you see is actually the ID of the serial-over-USB chip.
diff --git a/gpsd.xml b/gpsd.xml
index d62cee74..49489690 100644
--- a/gpsd.xml
+++ b/gpsd.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsd_json.c b/gpsd_json.c
index 510ff78a..9c04e9c8 100644
--- a/gpsd_json.c
+++ b/gpsd_json.c
@@ -10,7 +10,7 @@ of various core data structures in JSON.
 PERMISSIONS
   Written by Eric S. Raymond, 2009
   This file is Copyright (c) 2010 by the GPSD project
-  BSD terms apply: see the file COPYING in the distribution root for details.
+  SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/gpsd_json.xml b/gpsd_json.xml
index 88c8a665..0c7971d9 100644
--- a/gpsd_json.xml
+++ b/gpsd_json.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsdclient.c b/gpsdclient.c
index 41f7f1e5..bdae15c9 100644
--- a/gpsdclient.c
+++ b/gpsdclient.c
@@ -2,7 +2,7 @@
  * gpsdclient.c -- support functions for GPSD clients
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/gpsdclient.h b/gpsdclient.h
index ba1aabfb..d988b751 100644
--- a/gpsdclient.h
+++ b/gpsdclient.h
@@ -2,7 +2,7 @@
  * gpsdclient.h -- common functions for GPSD clients
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/gpsdctl.c b/gpsdctl.c
index cd794184..91352e1d 100644
--- a/gpsdctl.c
+++ b/gpsdctl.c
@@ -1,7 +1,7 @@
 /* gpsdctl.c -- communicate with the control socket of a gpsd instance
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 #include <string.h>
diff --git a/gpsdctl.xml b/gpsdctl.xml
index 36209afe..d47128c9 100644
--- a/gpsdctl.xml
+++ b/gpsdctl.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsdecode.c b/gpsdecode.c
index 13779a8a..2b249fae 100644
--- a/gpsdecode.c
+++ b/gpsdecode.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/gpsdecode.xml b/gpsdecode.xml
index cfcc38eb..b7368dc7 100644
--- a/gpsdecode.xml
+++ b/gpsdecode.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsfake b/gpsfake
index 8382d988..5d6a7988 100755
--- a/gpsfake
+++ b/gpsfake
@@ -7,7 +7,7 @@
 # factored out so we can write other test programs with it.
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
 # Preserve this property!
diff --git a/gpsfake.xml b/gpsfake.xml
index 520989e9..e8331d47 100644
--- a/gpsfake.xml
+++ b/gpsfake.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsinit b/gpsinit
index f9d56086..833d24b2 100755
--- a/gpsinit
+++ b/gpsinit
@@ -3,7 +3,7 @@
 # gpsinit - initialize kernel-CAN interfaces
 #
 # This file is Copyright (c) 2012 by the GPSD project.
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 
 speed=38400
diff --git a/gpsinit.xml b/gpsinit.xml
index 427a82b5..a3750023 100644
--- a/gpsinit.xml
+++ b/gpsinit.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsmon.c b/gpsmon.c
index a68c90f4..a495473d 100644
--- a/gpsmon.c
+++ b/gpsmon.c
@@ -2,7 +2,7 @@
  * The generic GPS packet monitor.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* for vsnprintf() FreeBSD wants __ISO_C_VISIBLE >= 1999 */
diff --git a/gpsmon.h b/gpsmon.h
index 95820272..574780a2 100644
--- a/gpsmon.h
+++ b/gpsmon.h
@@ -2,7 +2,7 @@
  *
  * By Eric S. Raymond, 2009
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef _GPSD_GPSMON_H_
diff --git a/gpsmon.xml b/gpsmon.xml
index c367331b..8c7aff40 100644
--- a/gpsmon.xml
+++ b/gpsmon.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpspacket.c b/gpspacket.c
index bbeefb12..8bf43872 100644
--- a/gpspacket.c
+++ b/gpspacket.c
@@ -2,7 +2,7 @@
  * Python binding for the packet.c module.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/gpspipe.c b/gpspipe.c
index 479c03a5..26718aa4 100644
--- a/gpspipe.c
+++ b/gpspipe.c
@@ -19,7 +19,7 @@
  * Original code by: Gary E. Miller <gem@rellim.com>.  Cleanup by ESR.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/gpspipe.xml b/gpspipe.xml
index 8021591d..da0a2c53 100644
--- a/gpspipe.xml
+++ b/gpspipe.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpsprof b/gpsprof
index 2e3ccb0e..fecbd47a 100755
--- a/gpsprof
+++ b/gpsprof
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # Collect and plot latency-profiling data from a running gpsd.
 # Requires gnuplot.
diff --git a/gpsprof.xml b/gpsprof.xml
index 78ecd2e3..d7151050 100644
--- a/gpsprof.xml
+++ b/gpsprof.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/gpssim.py b/gpssim.py
index b395f0b3..305d67fe 100644
--- a/gpssim.py
+++ b/gpssim.py
@@ -1,5 +1,5 @@
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 """
 A GPS simulator.
 
diff --git a/gpsutils.c b/gpsutils.c
index 396d24cb..c01b7bd3 100644
--- a/gpsutils.c
+++ b/gpsutils.c
@@ -1,7 +1,7 @@
 /* gpsutils.c -- code shared between low-level and high-level interfaces
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* The strptime prototype is not provided unless explicitly requested.
diff --git a/gpxlogger.c b/gpxlogger.c
index fda37ff7..63d40b51 100644
--- a/gpxlogger.c
+++ b/gpxlogger.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/gpxlogger.xml b/gpxlogger.xml
index 41c20c24..7d429941 100644
--- a/gpxlogger.xml
+++ b/gpxlogger.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2017 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/hex.c b/hex.c
index 80f0009a..446e4b4b 100644
--- a/hex.c
+++ b/hex.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <string.h>
 #include <ctype.h>
diff --git a/isgps.c b/isgps.c
index 30b4d107..ce08bd9e 100644
--- a/isgps.c
+++ b/isgps.c
@@ -54,7 +54,7 @@ handing GPS-subframe and RTCM decoding.
 You are not expected to understand any of this.
 
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 
 *****************************************************************************/
 
diff --git a/json.c b/json.c
index dd15cbf7..751120de 100644
--- a/json.c
+++ b/json.c
@@ -59,7 +59,7 @@ reusable module; search for "microjson".
 
 PERMISSIONS
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 #include <stdio.h>
diff --git a/json.h b/json.h
index 8180ef41..0d85b398 100644
--- a/json.h
+++ b/json.h
@@ -1,7 +1,7 @@
 /* Structures for JSON parsing using only fixed-extent memory
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdbool.h>
diff --git a/jsongen.py b/jsongen.py
index cf223a88..705af1d7 100755
--- a/jsongen.py
+++ b/jsongen.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # Never hand-hack what you can generate...
 #
diff --git a/leapsecond.py b/leapsecond.py
index 8efa786a..3047bba7 100755
--- a/leapsecond.py
+++ b/leapsecond.py
@@ -43,7 +43,7 @@ ftp://maia.usno.navy.mil/ser7/tai-utc.dat
 leapseconds.cache
 
 This file is Copyright (c) 2013 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 
 """
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
diff --git a/libgps.h b/libgps.h
index 70d4b7d3..91d2d2c6 100644
--- a/libgps.h
+++ b/libgps.h
@@ -1,7 +1,7 @@
 /* libgps.h -- prototypes for internals of the libgps library */
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #ifndef _GPSD_LIBGPS_H_
 #define _GPSD_LIBGPS_H_
diff --git a/libgps.xml b/libgps.xml
index a0e7571f..7e850c3d 100644
--- a/libgps.xml
+++ b/libgps.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
                    "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
diff --git a/libgps_core.c b/libgps_core.c
index 7ff31862..40b7425a 100644
--- a/libgps_core.c
+++ b/libgps_core.c
@@ -3,7 +3,7 @@
  * Core portion of client library.  Cals helpers to handle different eports.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* for vsnprintf() FreeBSD wants __ISO_C_VISIBLE >= 1999 */
diff --git a/libgps_json.c b/libgps_json.c
index 9ca02293..795e5d76 100644
--- a/libgps_json.c
+++ b/libgps_json.c
@@ -10,7 +10,7 @@ representations to libgps structures.
 PERMISSIONS
    Written by Eric S. Raymond, 2009
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/libgps_shm.c b/libgps_shm.c
index 992b32ae..c488c5bf 100644
--- a/libgps_shm.c
+++ b/libgps_shm.c
@@ -11,7 +11,7 @@ unmarshalling overhead.
 
 PERMISSIONS
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/libgps_sock.c b/libgps_sock.c
index 31f73f5c..c4303da5 100644
--- a/libgps_sock.c
+++ b/libgps_sock.c
@@ -1,7 +1,7 @@
 /* libgps_sock.c -- client interface library for the gpsd daemon
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/libgpsd_core.c b/libgpsd_core.c
index 86fa9485..85b8d86a 100644
--- a/libgpsd_core.c
+++ b/libgpsd_core.c
@@ -7,7 +7,7 @@
  * entry point has been retained.)
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifdef __linux__
diff --git a/libgpsmm.xml b/libgpsmm.xml
index 01dafbc7..cfcc9d35 100644
--- a/libgpsmm.xml
+++ b/libgpsmm.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
                    "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
diff --git a/maskaudit.py b/maskaudit.py
index 669f1e64..2985b649 100755
--- a/maskaudit.py
+++ b/maskaudit.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # With -p, dump a Python status mask list translated from the C one.
 #
diff --git a/matrix.c b/matrix.c
index 497946d2..4074cc9b 100644
--- a/matrix.c
+++ b/matrix.c
@@ -1,7 +1,7 @@
 /* matrix.c - matrix-algebra code
  *
  * This file is Copyright (c)2014 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <math.h>
 #include <stdbool.h>
diff --git a/matrix.h b/matrix.h
index 85ebbe01..24717874 100644
--- a/matrix.h
+++ b/matrix.h
@@ -2,7 +2,7 @@
  * matrix.h - matrix-algebra prototypes
  *
  * This file is Copyright (c)2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 extern bool matrix_invert(double mat[4][4], double inverse[4][4]);
diff --git a/monitor_garmin.c b/monitor_garmin.c
index 60016435..29c40db7 100644
--- a/monitor_garmin.c
+++ b/monitor_garmin.c
@@ -2,7 +2,7 @@
  * Garmin binary object for the GPS packet monitor.
  *
  * This file is Copyright (c) 2011 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <assert.h>
diff --git a/monitor_italk.c b/monitor_italk.c
index 3b547a81..3ded3933 100644
--- a/monitor_italk.c
+++ b/monitor_italk.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/monitor_nmea0183.c b/monitor_nmea0183.c
index a150ac48..b1648b9e 100644
--- a/monitor_nmea0183.c
+++ b/monitor_nmea0183.c
@@ -4,7 +4,7 @@
  * To do: Support for GPGLL, GPGBS, GPZDA, PASHR NMEA sentences.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* for vsnprintf() FreeBSD wants __ISO_C_VISIBLE >= 1999 */
diff --git a/monitor_oncore.c b/monitor_oncore.c
index 3d65d4f5..06bc0731 100644
--- a/monitor_oncore.c
+++ b/monitor_oncore.c
@@ -2,7 +2,7 @@
  * OnCore object for the GPS packet monitor.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <string.h>
diff --git a/monitor_proto.c b/monitor_proto.c
index b73a7717..007c6bce 100644
--- a/monitor_proto.c
+++ b/monitor_proto.c
@@ -2,7 +2,7 @@
  * Prototype file for a gpsmon monitor object.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/monitor_sirf.c b/monitor_sirf.c
index 314fa4a6..ffe59d78 100644
--- a/monitor_sirf.c
+++ b/monitor_sirf.c
@@ -2,7 +2,7 @@
  * SiRF object for the GPS packet monitor.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 #include <stdlib.h>
diff --git a/monitor_superstar2.c b/monitor_superstar2.c
index 489c7a8f..c75ec1c9 100644
--- a/monitor_superstar2.c
+++ b/monitor_superstar2.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include "gpsd.h"
 #include "bits.h"
diff --git a/monitor_tnt.c b/monitor_tnt.c
index 38ae9c48..4649ac2d 100644
--- a/monitor_tnt.c
+++ b/monitor_tnt.c
@@ -2,7 +2,7 @@
  * monitor_tnt.c - gpsmon support for True North Revolution devices.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <assert.h>
 
diff --git a/monitor_ubx.c b/monitor_ubx.c
index 2ba82de8..30eb8473 100644
--- a/monitor_ubx.c
+++ b/monitor_ubx.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <math.h>
 #include <stdlib.h> /* for labs() */
diff --git a/net_dgpsip.c b/net_dgpsip.c
index 900e911a..fde7dd44 100644
--- a/net_dgpsip.c
+++ b/net_dgpsip.c
@@ -1,7 +1,7 @@
 /* net_dgpsip.c -- gather and dispatch DGPS data from DGPSIP servers
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <sys/types.h>
 #include <stdio.h>
diff --git a/net_gnss_dispatch.c b/net_gnss_dispatch.c
index b7a15b20..cd3e0450 100644
--- a/net_gnss_dispatch.c
+++ b/net_gnss_dispatch.c
@@ -1,7 +1,7 @@
 /* net_gnss_dispatch.c -- common interface to a number of Network GNSS services
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <string.h>
diff --git a/net_ntrip.c b/net_ntrip.c
index f53ea316..467db338 100644
--- a/net_ntrip.c
+++ b/net_ntrip.c
@@ -1,7 +1,7 @@
 /* net_ntrip.c -- gather and dispatch DGNSS data from Ntrip broadcasters
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/netlib.c b/netlib.c
index 4da16aaf..2112e1e1 100644
--- a/netlib.c
+++ b/netlib.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include "gpsd_config.h"
diff --git a/ntpshm.h b/ntpshm.h
index 02920401..cbd35f5d 100644
--- a/ntpshm.h
+++ b/ntpshm.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2015 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef GPSD_NTPSHM_H
diff --git a/ntpshmmon.c b/ntpshmmon.c
index 1fa0ac88..5c9de77f 100644
--- a/ntpshmmon.c
+++ b/ntpshmmon.c
@@ -1,7 +1,7 @@
 /* ntpshmmon.c -- monitor the inner end of an ntpshmwrite.connection
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  */
 
diff --git a/ntpshmmon.xml b/ntpshmmon.xml
index 343b3f18..5c7141c9 100644
--- a/ntpshmmon.xml
+++ b/ntpshmmon.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2010 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/ntpshmread.c b/ntpshmread.c
index 8283b6b4..700579b6 100644
--- a/ntpshmread.c
+++ b/ntpshmread.c
@@ -1,7 +1,7 @@
 /* ntpshmread.c -- monitor the inner end of an ntpshmwrite.connection
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * Some of this was swiped from the NTPD distribution.
  */
diff --git a/os_compat.c b/os_compat.c
index cc7b27af..b1a167fb 100644
--- a/os_compat.c
+++ b/os_compat.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2017 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * This file contains functions to deal with compatibility issues across OSes.
  *
diff --git a/os_compat.h b/os_compat.h
index 2b4189f0..b7b6e09d 100644
--- a/os_compat.h
+++ b/os_compat.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2017 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * This is the header for os_compat.c, which contains functions dealing with
  * compatibility issues across OSes.
diff --git a/packet.c b/packet.c
index bf0e2757..a04a5b5b 100644
--- a/packet.c
+++ b/packet.c
@@ -24,7 +24,7 @@ others apart and distinguish them from baud barf.
 
 PERMISSIONS
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 #include <sys/types.h>
diff --git a/ppscheck.xml b/ppscheck.xml
index 2de0c23c..8a5bdc12 100644
--- a/ppscheck.xml
+++ b/ppscheck.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="ISO-8859-1"?>
 <!--
 This file is Copyright (c) 2016 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 -->
 <!DOCTYPE refentry PUBLIC
    "-//OASIS//DTD DocBook XML V4.1.2//EN"
diff --git a/ppsthread.h b/ppsthread.h
index 3d5f696e..8f0dd5b1 100644
--- a/ppsthread.h
+++ b/ppsthread.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2015 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef PPSTHREAD_H
diff --git a/pseudoais.c b/pseudoais.c
index 9c0503c6..ed8d0255 100644
--- a/pseudoais.c
+++ b/pseudoais.c
@@ -6,7 +6,7 @@
  * This file is build from driver_ais.c
  *
  * This file is Copyright (c) 2013 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdlib.h>
 #include <string.h>
diff --git a/pseudonmea.c b/pseudonmea.c
index 4dcc663f..95ea8d11 100644
--- a/pseudonmea.c
+++ b/pseudonmea.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/python_compatibility.h b/python_compatibility.h
index 635cd06c..3d31d0dc 100644
--- a/python_compatibility.h
+++ b/python_compatibility.h
@@ -2,7 +2,7 @@
  * python_compatibility.h -- macros for Python 2/3 compatibility
  *
  * This file is Copyright (c) 2016 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  *
  * Definitions based on examples in "Supporting Python 3 - The Book Site"
  *     http://python3porting.com/cextensions.html
diff --git a/rtcm2_json.c b/rtcm2_json.c
index d094e94b..82c21935 100644
--- a/rtcm2_json.c
+++ b/rtcm2_json.c
@@ -9,7 +9,7 @@ representations to libgps structures.
 
 PERMISSIONS
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/rtcm3_json.c b/rtcm3_json.c
index 75f66786..0a343d06 100644
--- a/rtcm3_json.c
+++ b/rtcm3_json.c
@@ -9,7 +9,7 @@ representations to libgps structures.
 
 PERMISSIONS
    This file is Copyright (c) 2013 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/sd_socket.c b/sd_socket.c
index 8c8c7719..ff725053 100644
--- a/sd_socket.c
+++ b/sd_socket.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2011 by Eckhart Wörner
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <limits.h>
diff --git a/sd_socket.h b/sd_socket.h
index 67363ff7..bc07a61b 100644
--- a/sd_socket.h
+++ b/sd_socket.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2011 by Eckhart Wörner
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef GPSD_SD_SOCKET_H
diff --git a/serial.c b/serial.c
index b8a06408..2c171f21 100644
--- a/serial.c
+++ b/serial.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /* cfmakeraw() needs _DEFAULT_SOURCE */
diff --git a/shared_json.c b/shared_json.c
index 3cabccc4..b455081c 100644
--- a/shared_json.c
+++ b/shared_json.c
@@ -11,7 +11,7 @@ the daemon and the client library.
 PERMISSIONS
   Written by Eric S. Raymond, 2009
   This file is Copyright (c) 2010 by the GPSD project
-  BSD terms apply: see the file COPYING in the distribution root for details.
+  SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/shmexport.c b/shmexport.c
index 806b85c2..79a27ba6 100644
--- a/shmexport.c
+++ b/shmexport.c
@@ -11,7 +11,7 @@ unmarshalling overhead.
 
 PERMISSIONS
    This file is Copyright (c) 2010 by the GPSD project
-   BSD terms apply: see the file COPYING in the distribution root for details.
+   SPDX-License-Identifier: BSD-2-clause
 
 ***************************************************************************/
 
diff --git a/subframe.c b/subframe.c
index 58204634..56a8a179 100644
--- a/subframe.c
+++ b/subframe.c
@@ -1,7 +1,7 @@
 /* subframe.c -- interpret satellite subframe data.
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <math.h>
 
diff --git a/test_bits.c b/test_bits.c
index 3a30c113..b474996a 100644
--- a/test_bits.c
+++ b/test_bits.c
@@ -1,7 +1,7 @@
 /* test harness for bits.h
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <inttypes.h>
diff --git a/test_float.c b/test_float.c
index 0b1d785c..8d17f218 100644
--- a/test_float.c
+++ b/test_float.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 
diff --git a/test_geoid.c b/test_geoid.c
index eeed567d..b863c85f 100644
--- a/test_geoid.c
+++ b/test_geoid.c
@@ -1,7 +1,7 @@
 /* test driver for the ECEF to WGS84 conversions in geoid.c
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/test_json.c b/test_json.c
index 1d9d0f34..a4fd64c8 100644
--- a/test_json.c
+++ b/test_json.c
@@ -1,7 +1,7 @@
 /* json.c - unit test for JSON partsing into fixed-extent structures
  *
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdio.h>
diff --git a/test_mktime.c b/test_mktime.c
index cf07dc55..59890532 100644
--- a/test_mktime.c
+++ b/test_mktime.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdlib.h>
 #include <stdio.h>
diff --git a/test_packet.c b/test_packet.c
index 2ac523c4..5106e340 100644
--- a/test_packet.c
+++ b/test_packet.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/timebase.c b/timebase.c
index 227736d0..c6728ab2 100644
--- a/timebase.c
+++ b/timebase.c
@@ -186,7 +186,7 @@ NTP clock skew goes over 1 second, but this is unlikely to ever happen
 idiosyncracies.
 
 This file is Copyright (c) 2010 -- 2013 by the GPSD project
-BSD terms apply: see the file COPYING in the distribution root for details.
+SPDX-License-Identifier: BSD-2-clause
 
 *****************************************************************************/
 
diff --git a/timespec.h b/timespec.h
index ae4c760e..a7eb96ec 100644
--- a/timespec.h
+++ b/timespec.h
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2015 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #ifndef GPSD_TIMESPEC_H
diff --git a/timespec_str.c b/timespec_str.c
index e297d14b..ac52edf9 100644
--- a/timespec_str.c
+++ b/timespec_str.c
@@ -1,6 +1,6 @@
 /*
  * This file is Copyright (c) 2010 by the GPSD project
- * BSD terms apply: see the file COPYING in the distribution root for details.
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 /*
diff --git a/valgrind-audit.py b/valgrind-audit.py
index 9254d0d4..749b2fa9 100755
--- a/valgrind-audit.py
+++ b/valgrind-audit.py
@@ -5,7 +5,7 @@
 # malloc and friends in the daemon.
 #
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
 # Preserve this property!
diff --git a/xgps b/xgps
index 16086d95..848ca622 100755
--- a/xgps
+++ b/xgps
@@ -8,7 +8,7 @@ usage: xgps [-D level] [-hV?] [-l degmfmt] [-u units] [-r rotation]
 '''
 
 # This file is Copyright (c) 2010 by the GPSD project
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 #
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
 # Preserve this property!
diff --git a/xgpsspeed b/xgpsspeed
index 936fc65c..06da1f22 100755
--- a/xgpsspeed
+++ b/xgpsspeed
@@ -5,7 +5,7 @@
 # and
 # Chen Wei <weichen302@gmx.com> (nautical mode)
 #
-# BSD terms apply: see the file COPYING in the distribution root for details.
+# SPDX-License-Identifier: BSD-2-clause
 
 # This code runs compatibly under Python 2 and 3.x for x >= 2.
 # Preserve this property!