summaryrefslogtreecommitdiff
path: root/src/preproc/refer/refer.man
blob: b7ef6762956a6126a96ace8624eac3287cf7d294 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
.ig
Copyright (C) 1989-2000, 2001, 2002, 2003, 2004, 2005, 2006, 2009, 2010
  Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be included in
translations approved by the Free Software Foundation instead of in
the original English.
..
.
.
.de TQ
.  br
.  ns
.  TP \\$1
..
.
.
.\" Like TP, but if specified indent is more than half
.\" the current line-length - indent, use the default indent.
.de Tp
.  ie \\n(.$=0:((0\\$1)*2u>(\\n(.lu-\\n(.iu)) .TP
.  el .TP "\\$1"
.
.
..
.\" The BSD man macros can't handle " in arguments to font change macros,
.\" so use \(ts instead of ".
.tr \(ts"
.
.
.TH @G@REFER @MAN1EXT@ "@MDATE@" "Groff Version @VERSION@"
.
.
.
.SH NAME
@g@refer \- preprocess bibliographic references for groff
.
.
.
.SH SYNOPSIS
.nr a \n(.j
.ad l
.nr i \n(.i
.in +\w'\fB@g@refer 'u
.ti \niu
.B @g@refer
.
.de OP
.  ie \\n(.$-1 .RI "[\ \fB\\$1\fP" "\\$2" "\ ]"
.  el .RB "[\ " "\\$1" "\ ]"
..
.
.OP \-benvCPRS
.OP \-a n
.OP \-c fields
.OP \-f n
.OP \-i fields
.OP \-k field
.OP \-l m,n
.OP \-p \%filename
.OP \-s fields
.OP \-t n
.OP \-B field.macro
.RI [\  \%filename \|.\|.\|.\ ]
.br
.ad \na
.
.SH DESCRIPTION
This file documents the GNU version of
.BR refer ,
which is part of the groff document formatting system.
.B refer
copies the contents of
.IR filename \|.\|.\|.\&
to the standard output,
except that lines between
.B .[
and
.B .]\&
are interpreted as citations,
and lines between
.B .R1
and
.B .R2
are interpreted as commands about how citations are to be processed.
.
.LP
Each citation specifies a reference.
The citation can specify a reference that is contained in
a bibliographic database by giving a set of keywords
that only that reference contains.
Alternatively it can specify a reference by supplying a database
record in the citation.
A combination of these alternatives is also possible.
.
.LP
For each citation,
.B refer
can produce a mark in the text.
This mark consists of some label which can be separated from
the text and from other labels in various ways.
For each reference it also outputs
.B groff
commands that can be used by a macro package to produce a formatted
reference for each citation.
The output of
.B refer
must therefore be processed using a suitable macro package.
The
.B \-ms
and
.B \-me
macros are both suitable.
The commands to format a citation's reference can be output immediately after
the citation,
or the references may be accumulated,
and the commands output at some later point.
If the references are accumulated, then multiple citations of the same
reference will produce a single formatted reference.
.
.LP
The interpretation of lines between
.B .R1
and
.B .R2
as commands is a new feature of GNU
.BR refer .
Documents making use of this feature can still be processed by
Unix refer just by adding the lines
.
.RS
.LP
.nf
.ft B
\&.de R1
\&.ig R2
\&..
.ft
.fi
.RE
.
to the beginning of the document.
This will cause
.B troff
to ignore everything between
.B .R1
and
.BR .R2 .
The effect of some commands can also be achieved by options.
These options are supported mainly for compatibility with Unix refer.
It is usually more convenient to use commands.
.
.LP
.B refer
generates
.B .lf
lines so that filenames and line numbers in messages produced
by commands that read
.B refer
output will be correct;
it also interprets lines beginning with
.B .lf
so that filenames and line numbers in the messages and
.B .lf
lines that it produces will be accurate even if the input has been
preprocessed by a command such as
.BR @g@soelim (@MAN1EXT@).
.
.
.
.SH OPTIONS
.
.LP
It is possible to have whitespace between a command line option and its
parameter.
.
.LP
Most options are equivalent to commands
(for a description of these commands see the
.B Commands
subsection):
.
.nr a \n(.j
.ad l
.TP
.B \-b
.B "no-label-in-text; no-label-in-reference"
.
.TP
.B \-e
.B accumulate
.
.TP
.B \-n
.B no-default-database
.
.TP
.B \-C
.B compatible
.
.TP
.B \-P
.B move-punctuation
.
.TP
.B \-S
.B
label\ "(A.n|Q)\ ',\ '\ (D.y|D)"; \%bracket-label\ "\ ("\ )\ ";\ "
.
.TP
.BI \-a n
.B reverse
.BI A n
.
.TP
.BI \-c fields
.B capitalize
.I fields
.
.TP
.BI \-f n
.B label
.BI % n
.
.TP
.BI \-i fields
.B search-ignore
.I fields
.
.TP
.B \-k
.B label
.B L\(ti%a
.
.TP
.BI \-k field
.B label
.IB field \(ti%a
.
.TP
.B \-l
.B label
.BI A.nD.y%a
.
.TP
.BI \-l m
.B label
.BI A.n+ m D.y%a
.
.TP
.BI \-l, n
.B label
.BI A.nD.y\- n %a
.
.TP
.BI \-l m , n
.B label
.BI A.n+ m D.y\- n %a
.
.TP
.BI \-p filename
.B database
.I filename
.
.TP
.BI \-s spec
.B sort
.I spec
.
.TP
.BI \-t n
.B search-truncate
.I n
.ad \na
.
.LP
These options are equivalent to the following commands with the
addition that the filenames specified on the command line are
processed as if they were arguments to the
.B bibliography
command instead of in the normal way:
.
.TP
.B \-B
.B "annotate X AP; no-label-in-reference"
.
.TP
.BI \-B field . macro
.B annotate
.I field
.IB macro ;
.B no-label-in-reference
.
.LP
The following options have no equivalent commands:
.
.TP
.B \-v
Print the version number.
.
.TP
.B \-R
Don't recognize lines beginning with
.BR .R1 / .R2 .
.
.
.
.SH USAGE
.
.
.SS Bibliographic databases
The bibliographic database is a text file consisting of records
separated by one or more blank lines.
Within each record fields start with a
.B %
at the beginning of a line.
Each field has a one character name that immediately follows the
.BR % .
It is best to use only upper and lower case letters for the names
of fields.
The name of the field should be followed by exactly one space,
and then by the contents of the field.
Empty fields are ignored.
The conventional meaning of each field is as follows:
.
.TP
.B A
The name of an author.
If the name contains a title such as
.B Jr.\&
at the end,
it should be separated from the last name by a comma.
There can be multiple occurrences of the
.B A
field.
The order is significant.
It is a good idea always to supply an
.B A
field or a
.B Q
field.
.
.TP
.B B
For an article that is part of a book, the title of the book.
.
.TP
.B C
The place (city) of publication.
.
.TP
.B D
The date of publication.
The year should be specified in full.
If the month is specified, the name rather than the number of the month
should be used, but only the first three letters are required.
It is a good idea always to supply a
.B D
field;
if the date is unknown, a value such as
.B in press
or
.B unknown
can be used.
.
.TP
.B E
For an article that is part of a book, the name of an editor of the book.
Where the work has editors and no authors,
the names of the editors should be given as
.B A
fields and
.B ,\ (ed)
or
.B ,\ (eds)
should be appended to the last author.
.
.TP
.B G
US Government ordering number.
.
.TP
.B I
The publisher (issuer).
.
.TP
.B J
For an article in a journal, the name of the journal.
.
.TP
.B K
Keywords to be used for searching.
.
.TP
.B L
Label.
.
.TP
.B N
Journal issue number.
.
.TP
.B O
Other information.
This is usually printed at the end of the reference.
.
.TP
.B P
Page number.
A range of pages can be specified as
.IB m \- n\fR.
.
.TP
.B Q
The name of the author, if the author is not a person.
This will only be used if there are no
.B A
fields.
There can only be one
.B Q
field.
.
.TP
.B R
Technical report number.
.
.TP
.B S
Series name.
.
.TP
.B T
Title.
For an article in a book or journal,
this should be the title of the article.
.
.TP
.B V
Volume number of the journal or book.
.
.TP
.B X
Annotation.
.
.LP
For all fields except
.B A
and
.BR E ,
if there is more than one occurrence of a particular field in a record,
only the last such field will be used.
.
.LP
If accent strings are used, they should follow the character to be accented.
This means that the
.B AM
macro must be used with the
.B \-ms
macros.
Accent strings should not be quoted:
use one
.B \e
rather than two.
.
.
.SS Citations
The format of a citation is
.
.RS
.BI .[ opening-text
.br
.I "flags keywords"
.br
.I fields
.br
.BI .] closing-text
.RE
.
.LP
The
.IR opening-text ,
.IR closing-text
and
.I flags
components are optional.
Only one of the
.I keywords
and
.I fields
components need be specified.
.
.LP
The
.I keywords
component says to search the bibliographic databases for a reference
that contains all the words in
.IR keywords .
It is an error if more than one reference if found.
.
.LP
The
.I fields
components specifies additional fields to replace or supplement
those specified in the reference.
When references are being accumulated and the
.I keywords
component is non-empty,
then additional fields should be specified only on the first
occasion that a particular reference is cited,
and will apply to all citations of that reference.
.
.LP
The
.I opening-text
and
.I closing-text
component specifies strings to be used to bracket the label instead
of the strings specified in the
.B bracket-label
command.
If either of these components is non-empty,
the strings specified in the
.B bracket-label
command will not be used;
this behaviour can be altered using the
.B [
and
.B ]
flags.
Note that leading and trailing spaces are significant for these components.
.
.LP
The
.I flags
component is a list of
non-alphanumeric characters each of which modifies the treatment
of this particular citation.
Unix refer will treat these flags as part of the keywords and
so will ignore them since they are non-alphanumeric.
The following flags are currently recognized:
.
.TP
.B #
This says to use the label specified by the
.B short-label
command,
instead of that specified by the
.B label
command.
If no short label has been specified, the normal label will be used.
Typically the short label is used with author-date labels
and consists of only the date and possibly a disambiguating letter;
the
.B #
is supposed to be suggestive of a numeric type of label.
.
.TP
.B [
Precede
.I opening-text
with the first string specified in the
.B bracket-label
command.
.
.TP
.B ]
Follow
.I closing-text
with the second string specified in the
.B bracket-label
command.
.
.LP
One advantages of using the
.B [
and
.B ]
flags rather than including the brackets in
.I opening-text
and
.I closing-text
is that
you can change the style of bracket used in the document just by changing the
.B bracket-label
command.
Another advantage is that sorting and merging of citations
will not necessarily be inhibited if the flags are used.
.
.LP
If a label is to be inserted into the text,
it will be attached to the line preceding the
.B .[
line.
If there is no such line, then an extra line will be inserted before the
.B .[
line and a warning will be given.
.
.LP
There is no special notation for making a citation to multiple references.
Just use a sequence of citations, one for each reference.
Don't put anything between the citations.
The labels for all the citations will be attached to the line preceding
the first citation.
The labels may also be sorted or merged.
See the description of the
.B <>
label expression, and of the
.B sort-adjacent-labels
and
.B abbreviate-label-ranges
command.
A label will not be merged if its citation has a non-empty
.I opening-text
or
.IR closing-text .
However, the labels for a citation using the
.B ]
flag and without any
.I closing-text
immediately followed by a citation using the
.B [
flag and without any
.I opening-text
may be sorted and merged
even though the first citation's
.I opening-text
or the second citation's
.I closing-text
is non-empty.
(If you wish to prevent this just make the first citation's
.I closing-text
.BR \e& .)
.
.
.SS Commands
Commands are contained between lines starting with
.B .R1
and
.BR .R2 .
Recognition of these lines can be prevented by the
.B \-R
option.
When a
.B .R1
line is recognized any accumulated references are flushed out.
Neither
.B .R1
nor
.B .R2
lines,
nor anything between them
is output.
.
.LP
Commands are separated by newlines or
.BR ; s.
.B #
introduces a comment that extends to the end of the line
(but does not conceal the newline).
Each command is broken up into words.
Words are separated by spaces or tabs.
A word that begins with
.B \(ts
extends to the next
.B \(ts
that is not followed by another
.BR \(ts .
If there is no such
.B \(ts
the word extends to the end of the line.
Pairs of
.B \(ts
in a word beginning with
.B \(ts
collapse to a single
.BR \(ts .
Neither
.B #
nor
.B ;
are recognized inside
.BR \(ts s.
A line can be continued by ending it with
.BR \e ;
this works everywhere except after a
.BR # .
.
.LP
.ds n \fR*
Each command
.I name
that is marked with \*n has an associated negative command
.BI no- name
that undoes the effect of
.IR name .
For example, the
.B no-sort
command specifies that references should not be sorted.
The negative commands take no arguments.
.
.LP
In the following description each argument must be a single word;
.I field
is used for a single upper or lower case letter naming a field;
.I fields
is used for a sequence of such letters;
.I m
and
.I n
are used for a non-negative numbers;
.I string
is used for an arbitrary string;
.I filename
is used for the name of a file.
.
.Tp \w'\fBabbreviate-label-ranges'u+2n
.BI abbreviate\*n\  fields\ string1\ string2\ string3\ string4
Abbreviate the first names of
.IR fields .
An initial letter will be separated from another initial letter by
.IR string1 ,
from the last name by
.IR string2 ,
and from anything else
(such as a
.B von
or
.BR de )
by
.IR string3 .
These default to a period followed by a space.
In a hyphenated first name,
the initial of the first part of the name will be separated from the hyphen by
.IR string4 ;
this defaults to a period.
No attempt is made to handle any ambiguities that might
result from abbreviation.
Names are abbreviated before sorting and before
label construction.
.
.TP
.BI abbreviate-label-ranges\*n\  string
Three or more adjacent labels that refer to consecutive references
will be abbreviated to a label consisting
of the first label, followed by
.I string
followed by the last label.
This is mainly useful with numeric labels.
If
.I string
is omitted it defaults to
.BR \- .
.
.TP
.B accumulate\*n
Accumulate references instead of writing out each reference
as it is encountered.
Accumulated references will be written out whenever a reference
of the form
.
.RS
.IP
.B .[
.br
.B $LIST$
.br
.B .]
.
.LP
is encountered,
after all input files have been processed,
and whenever
.B .R1
line is recognized.
.RE
.
.TP
.BI annotate\*n\  field\ string
.I field
is an annotation;
print it at the end of the reference as a paragraph preceded by the line
.
.RS
.IP
.BI . string
.
.LP
If
.I string
is omitted it will default to
.BR AP ;
if
.I field
is also omitted it will default to
.BR X .
Only one field can be an annotation.
.RE
.
.TP
.BI articles\  string \fR\|.\|.\|.
.IR string \|.\|.\|.\&
are definite or indefinite articles, and should be ignored at the beginning of
.B T
fields when sorting.
Initially,
.BR the ,
.B a
and
.B an
are recognized as articles.
.
.TP
.BI bibliography\  filename \fR\|.\|.\|.
Write out all the references contained in the bibliographic databases
.IR filename \|.\|.\|.
This command should come last in a
.BR .R1 / .R2
block.
.
.TP
.BI bracket-label\  string1\ string2\ string3
In the text, bracket each label
with
.I string1
and
.IR string2 .
An occurrence of
.I string2
immediately followed by
.I string1
will be turned into
.IR string3 .
The default behaviour is
.
.RS
.IP
.B
bracket-label \e*([. \e*(.] ", "
.RE
.
.TP
.BI capitalize\  fields
Convert
.I fields
to caps and small caps.
.
.TP
.B compatible\*n
Recognize
.B .R1
and
.B .R2
even when followed by a character other than space or newline.
.
.TP
.BI database\  filename \fR\|.\|.\|.
Search the bibliographic databases
.IR filename \|.\|.\|.
For each
.I filename
if an index
.IB filename @INDEX_SUFFIX@
created by
.BR @g@indxbib (@MAN1EXT@)
exists, then it will be searched instead;
each index can cover multiple databases.
.
.TP
.BI date-as-label\*n\  string
.I string
is a label expression that specifies a string with which to replace the
.B D
field after constructing the label.
See the
.B "Label expressions"
subsection for a description of label expressions.
This command is useful if you do not want explicit labels in the
reference list, but instead want to handle any necessary
disambiguation by qualifying the date in some way.
The label used in the text would typically be some combination of the
author and date.
In most cases you should also use the
.B no-label-in-reference
command.
For example,
.
.RS
.IP
.B "date-as-label D.+yD.y%a*D.-y"
.
.LP
would attach a disambiguating letter to the year part of the
.B D
field in the reference.
.RE
.
.TP
.B default-database\*n
The default database should be searched.
This is the default behaviour, so the negative version of
this command is more useful.
.B refer
determines whether the default database should be searched
on the first occasion that it needs to do a search.
Thus a
.B no-default-database
command must be given before then,
in order to be effective.
.
.TP
.BI discard\*n\  fields
When the reference is read,
.I fields
should be discarded;
no string definitions for
.I fields
will be output.
Initially,
.I fields
are
.BR XYZ .
.
.TP
.BI et-al\*n\  string\ m\ n
Control use of
.B "et al"
in the evaluation of
.B @
expressions in label expressions.
If the number of authors needed to make the author sequence
unambiguous is
.I u
and the total number of authors is
.I t
then the last
.IR t \|\-\| u
authors will be replaced by
.I string
provided that
.IR t \|\-\| u
is not less than
.I m
and
.I t
is not less than
.IR n .
The default behaviour is
.
.RS
.IP
.B
et-al " et al" 2 3
.RE
.
.TP
.BI include\  filename
Include
.I filename
and interpret the contents as commands.
.
.TP
.BI join-authors\  string1\ string2\ string3
This says how authors should be joined together.
When there are exactly two authors, they will be joined with
.IR string1 .
When there are more than two authors, all but the last two will
be joined with
.IR string2 ,
and the last two authors will be joined with
.IR string3 .
If
.I string3
is omitted,
it will default to
.IR string1 ;
if
.I string2
is also omitted it will also default to
.IR string1 .
For example,
.
.RS
.IP
.B
join-authors " and " ", " ", and "
.
.LP
will restore the default method for joining authors.
.RE
.
.TP
.B label-in-reference\*n
When outputting the reference,
define the string
.B [F
to be the reference's label.
This is the default behaviour; so the negative version
of this command is more useful.
.
.TP
.B label-in-text\*n
For each reference output a label in the text.
The label will be separated from the surrounding text as described in the
.B bracket-label
command.
This is the default behaviour; so the negative version
of this command is more useful.
.
.TP
.BI label\  string
.I string
is a label expression describing how to label each reference.
.
.TP
.BI separate-label-second-parts\  string
When merging two-part labels, separate the second part of the second
label from the first label with
.IR string .
See the description of the
.B <>
label expression.
.
.TP
.B move-punctuation\*n
In the text, move any punctuation at the end of line past the label.
It is usually a good idea to give this command unless you are using
superscripted numbers as labels.
.
.TP
.BI reverse\*n\  string
Reverse the fields whose names
are in
.IR string .
Each field name can be followed by a number which says
how many such fields should be reversed.
If no number is given for a field, all such fields will be reversed.
.
.TP
.BI search-ignore\*n\  fields
While searching for keys in databases for which no index exists,
ignore the contents of
.IR fields .
Initially, fields
.B XYZ
are ignored.
.
.TP
.BI search-truncate\*n\  n
Only require the first
.I n
characters of keys to be given.
In effect when searching for a given key
words in the database are truncated to the maximum of
.I n
and the length of the key.
Initially
.I n
is\ 6.
.
.TP
.BI short-label\*n\  string
.I string
is a label expression that specifies an alternative (usually shorter)
style of label.
This is used when the
.B #
flag is given in the citation.
When using author-date style labels, the identity of the author
or authors is sometimes clear from the context, and so it
may be desirable to omit the author or authors from the label.
The
.B short-label
command will typically be used to specify a label containing just
a date and possibly a disambiguating letter.
.
.TP
.BI sort\*n\  string
Sort references according to
.BR string .
References will automatically be accumulated.
.I string
should be a list of field names, each followed by a number,
indicating how many fields with the name should be used for sorting.
.B +
can be used to indicate that all the fields with the name should be used.
Also
.B .\&
can be used to indicate the references should be sorted using the
(tentative) label.
(The
.B "Label expressions"
subsection describes the concept of a tentative label.)
.
.TP
.B sort-adjacent-labels\*n
Sort labels that are adjacent in the text according to their
position in the reference list.
This command should usually be given if the
.B abbreviate-label-ranges
command has been given,
or if the label expression contains a
.B <>
expression.
This will have no effect unless references are being accumulated.
.
.
.SS Label expressions
.
.LP
Label expressions can be evaluated both normally and tentatively.
The result of normal evaluation is used for output.
The result of tentative evaluation, called the
.IR "tentative label" ,
is used to gather the information
that normal evaluation needs to disambiguate the label.
Label expressions specified by the
.B date-as-label
and
.B short-label
commands are not evaluated tentatively.
Normal and tentative evaluation are the same for all types
of expression other than
.BR @ ,
.BR * ,
and
.B %
expressions.
The description below applies to normal evaluation,
except where otherwise specified.
.
.TP
.I field
.TQ
.I field\ n
The
.IR n -th
part of
.IR field .
If
.I n
is omitted, it defaults to\ 1.
.
.TP
.BI ' string '
The characters in
.I string
literally.
.
.TP
.B @
All the authors joined as specified by the
.B join-authors
command.
The whole of each author's name will be used.
However, if the references are sorted by author
(that is the sort specification starts with
.BR A+ ),
then authors' last names will be used instead, provided that this does
not introduce ambiguity,
and also an initial subsequence of the authors may be used
instead of all the authors, again provided that this does not
introduce ambiguity.
The use of only the last name for the
.IR i -th
author of some reference
is considered to be ambiguous if
there is some other reference,
such that the first
.IR i \|-\|1
authors of the references are the same,
the
.IR i -th
authors are not the same,
but the
.IR i -th
authors' last names are the same.
A proper initial subsequence of the sequence
of authors for some reference is considered to be ambiguous if there is
a reference with some other sequence of authors which also has
that subsequence as a proper initial subsequence.
When an initial subsequence of authors is used, the remaining
authors are replaced by the string specified by the
.B et-al
command;
this command may also specify additional requirements that must be
met before an initial subsequence can be used.
.B @
tentatively evaluates to a canonical representation of the authors,
such that authors that compare equally for sorting purpose
will have the same representation.
.
.TP
.BI % n
.TQ
.B %a
.TQ
.B %A
.TQ
.B %i
.TQ
.B %I
The serial number of the reference formatted according to the character
following the
.BR % .
The serial number of a reference is\ 1 plus the number of earlier references
with same tentative label as this reference.
These expressions tentatively evaluate to an empty string.
.
.TP
.IB expr *
If there is another reference with the same tentative label as
this reference, then
.IR expr ,
otherwise an empty string.
It tentatively evaluates to an empty string.
.
.TP
.IB expr + n
.TQ
.IB expr \- n
The first
.RB ( + )
or last
.RB ( \- )
.I n
upper or lower case letters or digits of
.IR expr .
Troff special characters (such as
.BR \e('a )
count as a single letter.
Accent strings are retained but do not count towards the total.
.
.TP
.IB expr .l
.I expr
converted to lowercase.
.
.TP
.IB expr .u
.I expr
converted to uppercase.
.
.TP
.IB expr .c
.I expr
converted to caps and small caps.
.
.TP
.IB expr .r
.I expr
reversed so that the last name is first.
.
.TP
.IB expr .a
.I expr
with first names abbreviated.
Note that fields specified in the
.B abbreviate
command are abbreviated before any labels are evaluated.
Thus
.B .a
is useful only when you want a field to be abbreviated in a label
but not in a reference.
.
.TP
.IB expr .y
The year part of
.IR expr .
.
.TP
.IB expr .+y
The part of
.I expr
before the year, or the whole of
.I expr
if it does not contain a year.
.
.TP
.IB expr .\-y
The part of
.I expr
after the year, or an empty string if
.I expr
does not contain a year.
.
.TP
.IB expr .n
The last name part of
.IR expr .
.
.TP
.IB expr1 \(ti expr2
.I expr1
except that if the last character of
.I expr1
is
.B \-
then it will be replaced by
.IR expr2 .
.
.TP
.I expr1\ expr2
The concatenation of
.I expr1
and
.IR expr2 .
.
.TP
.IB expr1 | expr2
If
.I expr1
is non-empty then
.I expr1
otherwise
.IR expr2 .
.
.TP
.IB expr1 & expr2
If
.I expr1
is non-empty
then
.I expr2
otherwise an empty string.
.
.TP
.IB expr1 ? expr2 : expr3
If
.I expr1
is non-empty
then
.I expr2
otherwise
.IR expr3 .
.
.TP
.BI < expr >
The label is in two parts, which are separated by
.IR expr .
Two adjacent two-part labels which have the same first part will be
merged by appending the second part of the second label onto the first
label separated by the string specified in the
.B separate-label-second-parts
command (initially, a comma followed by a space); the resulting label
will also be a two-part label with the same first part as before
merging, and so additional labels can be merged into it.
Note that it is permissible for the first part to be empty;
this maybe desirable for expressions used in the
.B short-label
command.
.
.TP
.BI ( expr )
The same as
.IR expr .
Used for grouping.
.
.LP
The above expressions are listed in order of precedence
(highest first);
.B &
and
.B |
have the same precedence.
.
.
.SS Macro interface
Each reference starts with a call to the macro
.BR ]- .
The string
.B [F
will be defined to be the label for this reference,
unless the
.B no-label-in-reference
command has been given.
There then follows a series of string definitions,
one for each field:
string
.BI [ X
corresponds to field
.IR X .
The number register
.B [P
is set to\ 1 if the
.B P
field contains a range of pages.
The
.BR [T ,
.B [A
and
.B [O
number registers are set to\ 1 according as the
.BR T ,
.B A
and
.B O
fields end with one of the characters
.BR .?! .
The
.B [E
number register will be set to\ 1 if the
.B [E
string contains more than one name.
The reference is followed by a call to the
.B ][
macro.
The first argument to this macro gives a number representing
the type of the reference.
If a reference contains a
.B J
field, it will be classified as type\ 1,
otherwise if it contains a
.B B
field, it will type\ 3,
otherwise if it contains a
.B G
or
.B R
field it will be type\ 4,
otherwise if contains a
.B I
field it will be type\ 2,
otherwise it will be type\ 0.
The second argument is a symbolic name for the type:
.BR other ,
.BR journal-article ,
.BR book ,
.B article-in-book
or
.BR tech-report .
Groups of references that have been accumulated
or are produced by the
.B bibliography
command are preceded by a call to the
.B ]<
macro and followed by a call to the
.B ]>
macro.
.
.
.
.SH FILES
.
.Tp \w'\fB@DEFAULT_INDEX@'u+2n
.B @DEFAULT_INDEX@
Default database.
.
.TP
.IB file @INDEX_SUFFIX@
Index files.
.
.LP
.B refer
uses temporary files.
See the
.BR groff (@MAN1EXT@)
man page for details where such files are created.
.
.
.SH ENVIRONMENT
.
.Tp \w'\fBREFER'u+2n
.B REFER
If set, overrides the default database.
.
.
.
.SH "SEE ALSO"
.BR @g@indxbib (@MAN1EXT@),
.BR @g@lookbib (@MAN1EXT@),
.BR lkbib (@MAN1EXT@)
.br
.
.
.
.SH BUGS
In label expressions,
.B <>
expressions are ignored inside
.BI . char
expressions.
.
.\" Local Variables:
.\" mode: nroff
.\" End: