* tmac/groff_trace.man: Mention problem with `\\\\'.

1 files changed, 38 insertions, 2 deletions

diff --git a/tmac/groff_trace.man b/tmac/groff_trace.man
index bc1c98c1..bfcbd6f9 100644
--- a/tmac/groff_trace.man
+++ b/tmac/groff_trace.man
@@ -15,11 +15,11 @@ groff_trace.7
 
 File position: <groff-source>/tmac/groff_trace.man
 
-Last update: 14 July 2002
+Last update: 23 Oct 2006
 
 This file is part of groff, the GNU roff type-setting system.
 
-Copyright (C) 2002 Free Software Foundation, Inc.
+Copyright (C) 2002, 2006 Free Software Foundation, Inc.
 written by Bernd Warken <bwarken@mayn.de>
 
 Permission is granted to copy, distribute and/or modify this document
@@ -458,6 +458,42 @@ is fully protocolled.
 .
 .
 .\" --------------------------------------------------------------------
+.SH PROBLEMS
+.\" --------------------------------------------------------------------
+.
+Because
+.B trace.tmac
+wraps the
+.B .de
+request (and its cousins), macro arguments are expanded one level more.
+.
+This causes problems if an argument contains four backslashes or more
+to prevent too early expansion of the backslash.  For example, this
+macro call
+.
+.P
+.Example
+\&.foo \e\e\e\en[bar]
+./Example
+.
+.P
+normally passes `\e\en[bar]' to macro `.foo', but with the redefined
+.B .de
+request it passes `\en[bar]' instead.
+.
+.P
+The solution to this problem is to use groff's
+.B \eE
+escape which is an escape character not interpreted in copy mode, for
+example
+.
+.P
+.Example
+\&.foo \eEn[bar]
+./Example
+.
+.
+.\" --------------------------------------------------------------------
 .SH FILES
 .\" --------------------------------------------------------------------
 .