{ "mode": "man", "parameter": "refer", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/refer/1/json", "generated": "2026-06-16T10:27:32Z", "synopsis": "refer [-benCPRS] [-a n] [-c fields] [-f n] [-i fields] [-k field] [-l m,n] [-p filename]\n[-s fields] [-t n] -B field.macro [file ...]", "sections": { "NAME": { "content": "refer - preprocess bibliographic references for groff\n", "subsections": [] }, "SYNOPSIS": { "content": "refer [-benCPRS] [-a n] [-c fields] [-f n] [-i fields] [-k field] [-l m,n] [-p filename]\n[-s fields] [-t n] -B field.macro [file ...]\n", "subsections": [ { "name": "refer --help", "content": "" }, { "name": "refer -v", "content": "" }, { "name": "refer --version", "content": "" } ] }, "DESCRIPTION": { "content": "This file documents the GNU version of refer, which is part of the groff document formatting\nsystem. refer copies the contents of filename... to the standard output, except that lines\nbetween .[ and .] are interpreted as citations, and lines between .R1 and .R2 are interpreted\nas commands about how citations are to be processed.\n\nEach citation specifies a reference. The citation can specify a reference that is contained\nin a bibliographic database by giving a set of keywords that only that reference contains.\nAlternatively it can specify a reference by supplying a database record in the citation. A\ncombination of these alternatives is also possible.\n\nFor each citation, refer can produce a mark in the text. This mark consists of some label\nwhich can be separated from the text and from other labels in various ways. For each refer‐\nence it also outputs groff commands that can be used by a macro package to produce a format‐\nted reference for each citation. The output of refer must therefore be processed using a\nsuitable macro package. The -ms and -me macros are both suitable. The commands to format a\ncitation's reference can be output immediately after the citation, or the references may be\naccumulated, and the commands output at some later point. If the references are accumulated,\nthen multiple citations of the same reference will produce a single formatted reference.\n\nThe interpretation of lines between .R1 and .R2 as commands is a new feature of GNU refer.\nDocuments making use of this feature can still be processed by Unix refer just by adding the\nlines\n\n.de R1\n.ig R2\n..\nto the beginning of the document. This will cause troff to ignore everything between .R1 and\n.R2. The effect of some commands can also be achieved by options. These options are sup‐\nported mainly for compatibility with Unix refer. It is usually more convenient to use com‐\nmands.\n\nrefer generates .lf lines so that filenames and line numbers in messages produced by commands\nthat read refer output will be correct; it also interprets lines beginning with .lf so that\nfilenames and line numbers in the messages and .lf lines that it produces will be accurate\neven if the input has been preprocessed by a command such as soelim(1).\n", "subsections": [] }, "OPTIONS": { "content": "Whitespace is permitted between a command-line option and its argument.\n\nMost options are equivalent to commands (for a description of these commands, see subsection\n“Commands” below).\n", "subsections": [ { "name": "-b no-label-in-text; no-label-in-reference", "content": "", "flag": "-b" }, { "name": "-e accumulate", "content": "", "flag": "-e" }, { "name": "-n no-default-database", "content": "", "flag": "-n" }, { "name": "-C compatible", "content": "", "flag": "-C" }, { "name": "-P move-punctuation", "content": "", "flag": "-P" }, { "name": "-S label \"(A.n|Q) ', ' (D.y|D)\"; bracket-label \" (\" ) \"; \"", "content": "", "flag": "-S" }, { "name": "-a", "content": "", "flag": "-a" }, { "name": "-c", "content": "capitalize fields\n", "flag": "-c" }, { "name": "-f", "content": "", "flag": "-f" }, { "name": "-i", "content": "search-ignore fields\n", "flag": "-i" }, { "name": "-k label L~%a", "content": "", "flag": "-k" }, { "name": "-k", "content": "label field~%a\n", "flag": "-k" }, { "name": "-l label A.nD.y%a", "content": "", "flag": "-l" }, { "name": "-l", "content": "", "flag": "-l" }, { "name": "-l,", "content": "", "flag": "-l" }, { "name": "-l", "content": "", "flag": "-l" }, { "name": "-p", "content": "database filename\n", "flag": "-p" }, { "name": "-s", "content": "", "flag": "-s" }, { "name": "-t", "content": "These options are equivalent to the following commands with the addition that the filenames\nspecified on the command line are processed as if they were arguments to the bibliography\ncommand instead of in the normal way:\n", "flag": "-t" }, { "name": "-B annotate X AP; no-label-in-reference", "content": "", "flag": "-B" }, { "name": "-B", "content": "annotate field macro; no-label-in-reference\n\nThe following options have no equivalent commands:\n", "flag": "-B" }, { "name": "-v", "content": "", "flag": "-v" }, { "name": "-R", "content": "", "flag": "-R" } ] }, "USAGE": { "content": "", "subsections": [ { "name": "Bibliographic databases", "content": "The bibliographic database is a text file consisting of records separated by one or more\nblank lines. Within each record fields start with a % at the beginning of a line. Each\nfield has a one character name that immediately follows the %. It is best to use only upper\nand lower case letters for the names of fields. The name of the field should be followed by\nexactly one space, and then by the contents of the field. Empty fields are ignored. The\nconventional meaning of each field is as follows:\n\n%A The name of an author. If the name contains a title such as Jr. at the end, it should\nbe separated from the last name by a comma. There can be multiple occurrences of the\n%A field. The order is significant. It is a good idea always to supply an %A field\nor a %Q field.\n\n%B For an article that is part of a book, the title of the book.\n\n%C The place (city) of publication.\n\n%D The date of publication. The year should be specified in full. If the month is spec‐\nified, the name rather than the number of the month should be used, but only the first\nthree letters are required. It is a good idea always to supply a %D field; if the\ndate is unknown, a value such as in press or unknown can be used.\n\n%E For an article that is part of a book, the name of an editor of the book. Where the\nwork has editors and no authors, the names of the editors should be given as %A fields\nand , (ed) or , (eds) should be appended to the last author.\n\n%G US Government ordering number.\n\n%I The publisher (issuer).\n\n%J For an article in a journal, the name of the journal.\n\n%K Keywords to be used for searching.\n\n%L Label.\n\n%N Journal issue number.\n\n%O Other information. This is usually printed at the end of the reference.\n\n%P Page number. A range of pages can be specified as m-n.\n\n%Q The name of the author, if the author is not a person. This will only be used if\nthere are no %A fields. There can only be one %Q field.\n\n%R Technical report number.\n\n%S Series name.\n\n%T Title. For an article in a book or journal, this should be the title of the article.\n\n%V Volume number of the journal or book.\n\n%X Annotation.\n\nFor all fields except %A and %E, if there is more than one occurrence of a particular field\nin a record, only the last such field will be used.\n\nIf accent strings are used, they should follow the character to be accented. This means that\nthe AM macro must be used with the -ms macros. Accent strings should not be quoted: use one\n\\ rather than two.\n" }, { "name": "Citations", "content": "The format of a citation is\n.[opening-text\nflags keywords\nfields\n.]closing-text\n\nThe opening-text, closing-text, and flags components are optional. Only one of the keywords\nand fields components need be specified.\n\nThe keywords component says to search the bibliographic databases for a reference that con‐\ntains all the words in keywords. It is an error if more than one reference if found.\n\nThe fields components specifies additional fields to replace or supplement those specified in\nthe reference. When references are being accumulated and the keywords component is non-\nempty, then additional fields should be specified only on the first occasion that a particu‐\nlar reference is cited, and will apply to all citations of that reference.\n\nThe opening-text and closing-text component specifies strings to be used to bracket the label\ninstead of the strings specified in the bracket-label command. If either of these components\nis non-empty, the strings specified in the bracket-label command will not be used; this be‐\nhaviour can be altered using the [ and ] flags. Note that leading and trailing spaces are\nsignificant for these components.\n\nThe flags component is a list of non-alphanumeric characters each of which modifies the\ntreatment of this particular citation. Unix refer will treat these flags as part of the key‐\nwords and so will ignore them since they are non-alphanumeric. The following flags are cur‐\nrently recognized:\n\n# This says to use the label specified by the short-label command, instead of that spec‐\nified by the label command. If no short label has been specified, the normal label\nwill be used. Typically the short label is used with author-date labels and consists\nof only the date and possibly a disambiguating letter; the # is supposed to be sugges‐\ntive of a numeric type of label.\n\n[ Precede opening-text with the first string specified in the bracket-label command.\n\n] Follow closing-text with the second string specified in the bracket-label command.\n\nOne advantages of using the [ and ] flags rather than including the brackets in opening-text\nand closing-text is that you can change the style of bracket used in the document just by\nchanging the bracket-label command. Another advantage is that sorting and merging of cita‐\ntions will not necessarily be inhibited if the flags are used.\n\nIf a label is to be inserted into the text, it will be attached to the line preceding the .[\nline. If there is no such line, then an extra line will be inserted before the .[ line and a\nwarning will be given.\n\nThere is no special notation for making a citation to multiple references. Just use a se‐\nquence of citations, one for each reference. Don't put anything between the citations. The\nlabels for all the citations will be attached to the line preceding the first citation. The\nlabels may also be sorted or merged. See the description of the <> label expression, and of\nthe sort-adjacent-labels and abbreviate-label-ranges command. A label will not be merged if\nits citation has a non-empty opening-text or closing-text. However, the labels for a cita‐\ntion using the ] flag and without any closing-text immediately followed by a citation using\nthe [ flag and without any opening-text may be sorted and merged even though the first cita‐\ntion's opening-text or the second citation's closing-text is non-empty. (If you wish to pre‐\nvent this just make the first citation's closing-text \\&.)\n" }, { "name": "Commands", "content": "Commands are contained between lines starting with .R1 and .R2. Recognition of these lines\ncan be prevented by the -R option. When a .R1 line is recognized any accumulated references\nare flushed out. Neither .R1 nor .R2 lines, nor anything between them is output.\n\nCommands are separated by newlines or ;s. # introduces a comment that extends to the end of\nthe line (but does not conceal the newline). Each command is broken up into words. Words\nare separated by spaces or tabs. A word that begins with \" extends to the next \" that is not\nfollowed by another \". If there is no such \" the word extends to the end of the line. Pairs\nof \" in a word beginning with \" collapse to a single \". Neither # nor ; are recognized in‐\nside \"s. A line can be continued by ending it with \\; this works everywhere except after a\n#.\n\nEach command name that is marked with * has an associated negative command no-name that un‐\ndoes the effect of name. For example, the no-sort command specifies that references should\nnot be sorted. The negative commands take no arguments.\n\nIn the following description each argument must be a single word; field is used for a single\nupper or lower case letter naming a field; fields is used for a sequence of such letters; m\nand n are used for a non-negative numbers; string is used for an arbitrary string; filename\nis used for the name of a file.\n\nabbreviate* fields string1 string2 string3 string4\nAbbreviate the first names of fields. An initial letter will be separated from an‐\nother initial letter by string1, from the last name by string2, and from anything else\n(such as a von or de) by string3. These default to a period followed by a space. In\na hyphenated first name, the initial of the first part of the name will be separated\nfrom the hyphen by string4; this defaults to a period. No attempt is made to handle\nany ambiguities that might result from abbreviation. Names are abbreviated before\nsorting and before label construction.\n\nabbreviate-label-ranges* string\nThree or more adjacent labels that refer to consecutive references will be abbreviated\nto a label consisting of the first label, followed by string followed by the last la‐\nbel. This is mainly useful with numeric labels. If string is omitted it defaults to\n-.\n\naccumulate*\nAccumulate references instead of writing out each reference as it is encountered. Ac‐\ncumulated references will be written out whenever a reference of the form\n\n.[\n$LIST$\n.]\n\nis encountered, after all input files have been processed, and whenever .R1 line is\nrecognized.\n\nannotate* field string\nfield is an annotation; print it at the end of the reference as a paragraph preceded\nby the line\n\n.string\n\nIf string is omitted it will default to AP; if field is also omitted it will default\nto X. Only one field can be an annotation.\n\narticles string...\nstring... are definite or indefinite articles, and should be ignored at the beginning\nof T fields when sorting. Initially, the, a and an are recognized as articles.\n\nbibliography filename...\nWrite out all the references contained in the bibliographic databases filename...\nThis command should come last in a .R1/.R2 block.\n\nbracket-label string1 string2 string3\nIn the text, bracket each label with string1 and string2. An occurrence of string2\nimmediately followed by string1 will be turned into string3. The default behaviour is\n\nbracket-label \\*([. \\*(.] \", \"\n\ncapitalize fields\nConvert fields to caps and small caps.\n\ncompatible*\nRecognize .R1 and .R2 even when followed by a character other than space or newline.\n\ndatabase filename...\nSearch the bibliographic databases filename... For each filename if an index file‐\nname.i created by indxbib(1) exists, then it will be searched instead; each index can\ncover multiple databases.\n\ndate-as-label* string\nstring is a label expression that specifies a string with which to replace the D field\nafter constructing the label. See subsection “Label expressions” below for a descrip‐\ntion of label expressions. This command is useful if you do not want explicit labels\nin the reference list, but instead want to handle any necessary disambiguation by\nqualifying the date in some way. The label used in the text would typically be some\ncombination of the author and date. In most cases you should also use the no-label-\nin-reference command. For example,\n\ndate-as-label D.+yD.y%a*D.-y\n\nwould attach a disambiguating letter to the year part of the D field in the reference.\n\ndefault-database*\nThe default database should be searched. This is the default behaviour, so the nega‐\ntive version of this command is more useful. refer determines whether the default\ndatabase should be searched on the first occasion that it needs to do a search. Thus\na no-default-database command must be given before then, in order to be effective.\n\ndiscard* fields\nWhen the reference is read, fields should be discarded; no string definitions for\nfields will be output. Initially, fields are XYZ.\n\net-al* string m n\nControl use of et al in the evaluation of @ expressions in label expressions. If the\nnumber of authors needed to make the author sequence unambiguous is u and the total\nnumber of authors is t then the last t-u authors will be replaced by string provided\nthat t-u is not less than m and t is not less than n. The default behaviour is\n\net-al \" et al\" 2 3\n\ninclude filename\nInclude filename and interpret the contents as commands.\n\njoin-authors string1 string2 string3\nThis says how authors should be joined together. When there are exactly two authors,\nthey will be joined with string1. When there are more than two authors, all but the\nlast two will be joined with string2, and the last two authors will be joined with\nstring3. If string3 is omitted, it will default to string1; if string2 is also omit‐\nted it will also default to string1. For example,\n\njoin-authors \" and \" \", \" \", and \"\n\nwill restore the default method for joining authors.\n\nlabel-in-reference*\nWhen outputting the reference, define the string [F to be the reference's label. This\nis the default behaviour; so the negative version of this command is more useful.\n\nlabel-in-text*\nFor each reference output a label in the text. The label will be separated from the\nsurrounding text as described in the bracket-label command. This is the default be‐\nhaviour; so the negative version of this command is more useful.\n\nlabel string\nstring is a label expression describing how to label each reference.\n\nseparate-label-second-parts string\nWhen merging two-part labels, separate the second part of the second label from the\nfirst label with string. See the description of the <> label expression.\n\nmove-punctuation*\nIn the text, move any punctuation at the end of line past the label. It is usually a\ngood idea to give this command unless you are using superscripted numbers as labels.\n\nreverse* string\nReverse the fields whose names are in string. Each field name can be followed by a\nnumber which says how many such fields should be reversed. If no number is given for\na field, all such fields will be reversed.\n\nsearch-ignore* fields\nWhile searching for keys in databases for which no index exists, ignore the contents\nof fields. Initially, fields XYZ are ignored.\n\nsearch-truncate* n\nOnly require the first n characters of keys to be given. In effect when searching for\na given key words in the database are truncated to the maximum of n and the length of\nthe key. Initially n is 6.\n\nshort-label* string\nstring is a label expression that specifies an alternative (usually shorter) style of\nlabel. This is used when the # flag is given in the citation. When using author-date\nstyle labels, the identity of the author or authors is sometimes clear from the con‐\ntext, and so it may be desirable to omit the author or authors from the label. The\nshort-label command will typically be used to specify a label containing just a date\nand possibly a disambiguating letter.\n\nsort* string\nSort references according to string. References will automatically be accumulated.\nstring should be a list of field names, each followed by a number, indicating how many\nfields with the name should be used for sorting. + can be used to indicate that all\nthe fields with the name should be used. Also . can be used to indicate the refer‐\nences should be sorted using the (tentative) label. (Subsection “Label expressions”\nbelow describes the concept of a tentative label.)\n\nsort-adjacent-labels*\nSort labels that are adjacent in the text according to their position in the reference\nlist. This command should usually be given if the abbreviate-label-ranges command has\nbeen given, or if the label expression contains a <> expression. This will have no\neffect unless references are being accumulated.\n" }, { "name": "Label expressions", "content": "Label expressions can be evaluated both normally and tentatively. The result of normal eval‐\nuation is used for output. The result of tentative evaluation, called the tentative label,\nis used to gather the information that normal evaluation needs to disambiguate the label.\nLabel expressions specified by the date-as-label and short-label commands are not evaluated\ntentatively. Normal and tentative evaluation are the same for all types of expression other\nthan @, *, and % expressions. The description below applies to normal evaluation, except\nwhere otherwise specified.\n\nfield\nfield n\nThe n-th part of field. If n is omitted, it defaults to 1.\n\n'string'\nThe characters in string literally.\n\n@ All the authors joined as specified by the join-authors command. The whole of each\nauthor's name will be used. However, if the references are sorted by author (that is\nthe sort specification starts with A+), then authors last names will be used instead,\nprovided that this does not introduce ambiguity, and also an initial subsequence of\nthe authors may be used instead of all the authors, again provided that this does not\nintroduce ambiguity. The use of only the last name for the i-th author of some refer‐\nence is considered to be ambiguous if there is some other reference, such that the\nfirst i-1 authors of the references are the same, the i-th authors are not the same,\nbut the i-th authors last names are the same. A proper initial subsequence of the se‐\nquence of authors for some reference is considered to be ambiguous if there is a ref‐\nerence with some other sequence of authors which also has that subsequence as a proper\ninitial subsequence. When an initial subsequence of authors is used, the remaining\nauthors are replaced by the string specified by the et-al command; this command may\nalso specify additional requirements that must be met before an initial subsequence\ncan be used. @ tentatively evaluates to a canonical representation of the authors,\nsuch that authors that compare equally for sorting purpose will have the same repre‐\nsentation.\n\n%n\n%a\n%A\n%i\n%I The serial number of the reference formatted according to the character following the\n%. The serial number of a reference is 1 plus the number of earlier references with\nsame tentative label as this reference. These expressions tentatively evaluate to an\nempty string.\n\nexpr* If there is another reference with the same tentative label as this reference, then\nexpr, otherwise an empty string. It tentatively evaluates to an empty string.\n\nexpr+n\nexpr-n The first (+) or last (-) n upper or lower case letters or digits of expr. Troff spe‐\ncial characters (such as \\('a) count as a single letter. Accent strings are retained\nbut do not count towards the total.\n\nexpr.l expr converted to lowercase.\n\nexpr.u expr converted to uppercase.\n\nexpr.c expr converted to caps and small caps.\n\nexpr.r expr reversed so that the last name is first.\n\nexpr.a expr with first names abbreviated. Note that fields specified in the abbreviate com‐\nmand are abbreviated before any labels are evaluated. Thus .a is useful only when you\nwant a field to be abbreviated in a label but not in a reference.\n\nexpr.y The year part of expr.\n\nexpr.+y\nThe part of expr before the year, or the whole of expr if it does not contain a year.\n\nexpr.-y\nThe part of expr after the year, or an empty string if expr does not contain a year.\n\nexpr.n The last name part of expr.\n\nexpr1~expr2\nexpr1 except that if the last character of expr1 is - then it will be replaced by\nexpr2.\n\nexpr1 expr2\nThe concatenation of expr1 and expr2.\n\nexpr1|expr2\nIf expr1 is non-empty then expr1 otherwise expr2.\n\nexpr1&expr2\nIf expr1 is non-empty then expr2 otherwise an empty string.\n\nexpr1?expr2:expr3\nIf expr1 is non-empty then expr2 otherwise expr3.\n\n The label is in two parts, which are separated by expr. Two adjacent two-part labels\nwhich have the same first part will be merged by appending the second part of the sec‐\nond label onto the first label separated by the string specified in the separate-la‐‐\nbel-second-parts command (initially, a comma followed by a space); the resulting label\nwill also be a two-part label with the same first part as before merging, and so addi‐\ntional labels can be merged into it. Note that it is permissible for the first part\nto be empty; this maybe desirable for expressions used in the short-label command.\n\n(expr) The same as expr. Used for grouping.\n\nThe above expressions are listed in order of precedence (highest first); & and | have the\nsame precedence.\n" }, { "name": "Macro interface", "content": "Each reference starts with a call to the macro ]-. The string [F will be defined to be the\nlabel for this reference, unless the no-label-in-reference command has been given. There\nthen follows a series of string definitions, one for each field: string [X corresponds to\nfield X. The number register [P is set to 1 if the P field contains a range of pages. The\n[T, [A and [O number registers are set to 1 according as the T, A and O fields end with one\nof the characters .?!. The [E number register will be set to 1 if the [E string contains\nmore than one name. The reference is followed by a call to the ][ macro. The first argument\nto this macro gives a number representing the type of the reference. If a reference contains\na J field, it will be classified as type 1, otherwise if it contains a B field, it will\ntype 3, otherwise if it contains a G or R field it will be type 4, otherwise if it contains\nan I field it will be type 2, otherwise it will be type 0. The second argument is a symbolic\nname for the type: other, journal-article, book, article-in-book or tech-report. Groups of\nreferences that have been accumulated or are produced by the bibliography command are pre‐\nceded by a call to the ]< macro and followed by a call to the ]> macro.\n" } ] }, "FILES": { "content": "/usr/dict/papers/Ind\nDefault database.\n\nfile.i Index files.\n\nrefer uses temporary files. See the groff(1) man page for details where such files are cre‐\nated.\n", "subsections": [] }, "ENVIRONMENT": { "content": "REFER If set, overrides the default database.\n", "subsections": [] }, "SEE ALSO": { "content": "indxbib(1), lookbib(1), lkbib(1)\n", "subsections": [] }, "BUGS": { "content": "In label expressions, <> expressions are ignored inside .char expressions.\n\n\n\ngroff 1.22.4 23 March 2022 REFER(1)", "subsections": [] } }, "summary": "refer - preprocess bibliographic references for groff", "flags": [ { "flag": "-b", "long": null, "arg": null, "description": "" }, { "flag": "-e", "long": null, "arg": null, "description": "" }, { "flag": "-n", "long": null, "arg": null, "description": "" }, { "flag": "-C", "long": null, "arg": null, "description": "" }, { "flag": "-P", "long": null, "arg": null, "description": "" }, { "flag": "-S", "long": null, "arg": null, "description": "" }, { "flag": "-a", "long": null, "arg": null, "description": "" }, { "flag": "-c", "long": null, "arg": null, "description": "capitalize fields" }, { "flag": "-f", "long": null, "arg": null, "description": "" }, { "flag": "-i", "long": null, "arg": null, "description": "search-ignore fields" }, { "flag": "-k", "long": null, "arg": null, "description": "" }, { "flag": "-k", "long": null, "arg": null, "description": "label field~%a" }, { "flag": "-l", "long": null, "arg": null, "description": "" }, { "flag": "-l", "long": null, "arg": null, "description": "" }, { "flag": "-l", "long": null, "arg": null, "description": "" }, { "flag": "-l", "long": null, "arg": null, "description": "" }, { "flag": "-p", "long": null, "arg": null, "description": "database filename" }, { "flag": "-s", "long": null, "arg": null, "description": "" }, { "flag": "-t", "long": null, "arg": null, "description": "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 bibliography command instead of in the normal way:" }, { "flag": "-B", "long": null, "arg": null, "description": "" }, { "flag": "-B", "long": null, "arg": null, "description": "annotate field macro; no-label-in-reference The following options have no equivalent commands:" }, { "flag": "-v", "long": null, "arg": null, "description": "" }, { "flag": "-R", "long": null, "arg": null, "description": "" } ], "examples": [], "see_also": [ { "name": "indxbib", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/indxbib/1/json" }, { "name": "lookbib", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/lookbib/1/json" }, { "name": "lkbib", "section": "1", "url": "https://www.chedong.com/phpMan.php/man/lkbib/1/json" } ] }