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REFER(1)                    General Commands Manual                   REFER(1)

       refer - preprocess bibliographic references for groff

refer [ -benvCPRS ] [ -an ] [ -cfields ] [ -fn ] [ -ifields ] [ -kfield ]
             [ -lm,n ] [ -pfilename ] [ -sfields ] [ -tn ] [ -Bfield.macro ]
             [ filename... ]

       It is possible to have whitespace between a command line option and its

       This file documents the GNU version of refer, which is part of the
       groff document formatting system.  refer copies the contents of
       filename... to the standard output, except that lines between .[ and .]
       are interpreted as citations, and lines between .R1 and .R2 are
       interpreted as commands about how citations are to be processed.

       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.

       For each citation, 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 groff
       commands that can be used by a macro package to produce a formatted
       reference for each citation.  The output of refer must therefore be
       processed using a suitable macro package.  The -ms and -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.

       The interpretation of lines between .R1 and .R2 as commands is a new
       feature of GNU refer.  Documents making use of this feature can still
       be processed by Unix refer just by adding the lines

              .de R1
              .ig R2
       to the beginning of the document.  This will cause troff to ignore
       everything between .R1 and .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

       refer generates .lf lines so that filenames and line numbers in
       messages produced by commands that read refer output will be correct;
       it also interprets lines beginning with .lf so that filenames and line
       numbers in the messages and .lf lines that it produces will be accurate
       even if the input has been preprocessed by a command such as soelim(1).

       Most options are equivalent to commands (for a description of these
       commands see the Commands subsection):

       -b     no-label-in-text; no-label-in-reference

       -e     accumulate

       -n     no-default-database

       -C     compatible

       -P     move-punctuation

       -S     label "(A.n|Q) ', ' (D.y|D)"; bracket-label " (" ) "; "

       -an    reverse An

              capitalize fields

       -fn    label %n

              search-ignore fields

       -k     label L~%a

              label field~%a

       -l     label A.nD.y%a

       -lm    label A.n+mD.y%a

       -l,n   label A.nD.y-n%a

       -lm,n  label A.n+mD.y-n%a

              database filename

       -sspec sort spec

       -tn    search-truncate n

       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:

       -B     annotate X AP; no-label-in-reference

              annotate field macro; no-label-in-reference

       The following options have no equivalent commands:

       -v     Print the version number.

       -R     Don't recognize lines beginning with .R1/.R2.

   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 % at the beginning of a line.  Each field has a one character
       name that immediately follows the %.  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:

       A      The name of an author.  If the name contains a title such as Jr.
              at the end, it should be separated from the last name by a
              comma.  There can be multiple occurrences of the A field.  The
              order is significant.  It is a good idea always to supply an A
              field or a Q field.

       B      For an article that is part of a book, the title of the book.

       C      The place (city) of publication.

       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 D field; if the
              date is unknown, a value such as in press or unknown can be

       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 A fields and , (ed) or , (eds)
              should be appended to the last author.

       G      US Government ordering number.

       I      The publisher (issuer).

       J      For an article in a journal, the name of the journal.

       K      Keywords to be used for searching.

       L      Label.

       N      Journal issue number.

       O      Other information.  This is usually printed at the end of the

       P      Page number.  A range of pages can be specified as m-n.

       Q      The name of the author, if the author is not a person.  This
              will only be used if there are no A fields.  There can only be
              one Q field.

       R      Technical report number.

       S      Series name.

       T      Title.  For an article in a book or journal, this should be the
              title of the article.

       V      Volume number of the journal or book.

       X      Annotation.

       For all fields except A and E, if there is more than one occurrence of
       a particular field in a record, only the last such field will be used.

       If accent strings are used, they should follow the character to be
       accented.  This means that the AM macro must be used with the -ms
       macros.  Accent strings should not be quoted: use one \ rather than

       The format of a citation is
              flags keywords

       The opening-text, closing-text and flags components are optional.  Only
       one of the keywords and fields components need be specified.

       The keywords component says to search the bibliographic databases for a
       reference that contains all the words in keywords.  It is an error if
       more than one reference if found.

       The fields components specifies additional fields to replace or
       supplement those specified in the reference.  When references are being
       accumulated and the 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.

       The opening-text and closing-text component specifies strings to be
       used to bracket the label instead of the strings specified in the
       bracket-label command.  If either of these components is non-empty, the
       strings specified in the bracket-label command will not be used; this
       behaviour can be altered using the [ and ] flags.  Note that leading
       and trailing spaces are significant for these components.

       The 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

       #      This says to use the label specified by the short-label command,
              instead of that specified by the 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 # is supposed to be suggestive of a numeric type of label.

       [      Precede opening-text with the first string specified in the
              bracket-label command.

       ]      Follow closing-text with the second string specified in the
              bracket-label command.

       One advantages of using the [ and ] flags rather than including the
       brackets in opening-text and closing-text is that you can change the
       style of bracket used in the document just by changing the
       bracket-label command.  Another advantage is that sorting and merging
       of citations will not necessarily be inhibited if the flags are used.

       If a label is to be inserted into the text, it will be attached to the
       line preceding the .[ line.  If there is no such line, then an extra
       line will be inserted before the .[ line and a warning will be given.

       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 <>
       label expression, and of the sort-adjacent-labels and
       abbreviate-label-ranges command.  A label will not be merged if its
       citation has a non-empty opening-text or closing-text.  However, the
       labels for a citation using the ] flag and without any closing-text
       immediately followed by a citation using the [ flag and without any
       opening-text may be sorted and merged even though the first citation's
       opening-text or the second citation's closing-text is non-empty.  (If
       you wish to prevent this just make the first citation's closing-text

       Commands are contained between lines starting with .R1 and .R2.
       Recognition of these lines can be prevented by the -R option.  When a
       .R1 line is recognized any accumulated references are flushed out.
       Neither .R1 nor .R2 lines, nor anything between them is output.

       Commands are separated by newlines or ;s.  # 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 " extends to the next " that is not
       followed by another ".  If there is no such " the word extends to the
       end of the line.  Pairs of " in a word beginning with " collapse to a
       single ".  Neither # nor ; are recognized inside "s.  A line can be
       continued by ending it with \; this works everywhere except after a #.

       Each command name that is marked with * has an associated negative
       command no-name that undoes the effect of name.  For example, the
       no-sort command specifies that references should not be sorted.  The
       negative commands take no arguments.

       In the following description each argument must be a single word; field
       is used for a single upper or lower case letter naming a field; fields
       is used for a sequence of such letters; m and n are used for a non-
       negative numbers; string is used for an arbitrary string; filename is
       used for the name of a file.

       abbreviate* fields string1 string2 string3 string4
              Abbreviate the first names of fields.  An initial letter will be
              separated from another initial letter by string1, from the last
              name by string2, and from anything else (such as a von or de) by
              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 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.

       abbreviate-label-ranges* string
              Three or more adjacent labels that refer to consecutive
              references will be abbreviated to a label consisting of the
              first label, followed by string followed by the last label.
              This is mainly useful with numeric labels.  If string is omitted
              it defaults to -.

              Accumulate references instead of writing out each reference as
              it is encountered.  Accumulated references will be written out
              whenever a reference of the form


              is encountered, after all input files hve been processed, and
              whenever .R1 line is recognized.

       annotate* field string
              field is an annotation; print it at the end of the reference as
              a paragraph preceded by the line


              If macro is omitted it will default to AP; if field is also
              omitted it will default to X.  Only one field can be an

       articles string...
              string... are definite or indefinite articles, and should be
              ignored at the beginning of T fields when sorting.  Initially,
              the, a and an are recognized as articles.

       bibliography filename...
              Write out all the references contained in the bibliographic
              databases filename...  This command should come last in a
              .R1/.R2 block.

       bracket-label string1 string2 string3
              In the text, bracket each label with string1 and string2.  An
              occurrence of string2 immediately followed by string1 will be
              turned into string3.  The default behaviour is

                     bracket-label \*([. \*(.] ", "

       capitalize fields
              Convert fields to caps and small caps.

              Recognize .R1 and .R2 even when followed by a character other
              than space or newline.

       database filename...
              Search the bibliographic databases filename...  For each
              filename if an index filename.i created by indxbib(1) exists,
              then it will be searched instead; each index can cover multiple

       date-as-label* string
              string is a label expression that specifies a string with which
              to replace the D field after constructing the label.  See the
              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
              no-label-in-reference command.  For example,

                     date-as-label D.+yD.y%a*D.-y

              would attach a disambiguating letter to the year part of the D
              field in the reference.

              The default database should be searched.  This is the default
              behaviour, so the negative version of this command is more
              useful.  refer determines whether the default database should be
              searched on the first occasion that it needs to do a search.
              Thus a no-default-database command must be given before then, in
              order to be effective.

       discard* fields
              When the reference is read, fields should be discarded; no
              string definitions for fields will be output.  Initially, fields
              are XYZ.

       et-al* string m n
              Control use of et al in the evaluation of @ expressions in label
              expressions.  If the number of authors needed to make the author
              sequence unambiguous is u and the total number of authors is t
              then the last t-u authors will be replaced by string provided
              that t-u is not less than m and t is not less than n.  The
              default behaviour is

                     et-al " et al" 2 3

       include filename
              Include filename and interpret the contents as commands.

       join-authors string1 string2 string3
              This says how authors should be joined together.  When there are
              exactly two authors, they will be joined with string1.  When
              there are more than two authors, all but the last two will be
              joined with string2, and the last two authors will be joined
              with string3.  If string3 is omitted, it will default to
              string1; if string2 is also omitted it will also default to
              string1.  For example,

                     join-authors " and " ", " ", and "

              will restore the default method for joining authors.

              When outputting the reference, define the string [F to be the
              reference's label.  This is the default behaviour; so the
              negative version of this command is more useful.

              For each reference output a label in the text.  The label will
              be separated from the surrounding text as described in the
              bracket-label command.  This is the default behaviour; so the
              negative version of this command is more useful.

       label string
              string is a label expression describing how to label each

       separate-label-second-parts string
              When merging two-part labels, separate the second part of the
              second label from the first label with string.  See the
              description of the <> label expression.

              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.

       reverse* string
              Reverse the fields whose names are in 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.

       search-ignore* fields
              While searching for keys in databases for which no index exists,
              ignore the contents of fields.  Initially, fields XYZ are

       search-truncate* n
              Only require the first 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 n and the length of the key.
              Initially n is 6.

       short-label* string
              string is a label expression that specifies an alternative
              (usually shorter) style of label.  This is used when the # 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 short-label command will typically
              be used to specify a label containing just a date and possibly a
              disambiguating letter.

       sort* string
              Sort references according to string.  References will
              automatically be accumulated.  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.  + can be used to
              indicate that all the fields with the name should be used.  Also
              . can be used to indicate the references should be sorted using
              the (tentative) label.  (The Label expressions subsection
              describes the concept of a tentative label.)

              Sort labels that are adjacent in the text according to their
              position in the reference list.  This command should usually be
              given if the abbreviate-label-ranges command has been given, or
              if the label expression contains a <> expression.  This will
              have no effect unless references are being accumulated.

   Label expressions
       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 tentative label, is used to gather the
       information that normal evaluation needs to disambiguate the label.
       Label expressions specified by the date-as-label and short-label
       commands are not evaluated tentatively.  Normal and tentative
       evaluation are the same for all types of expression other than @, *,
       and % expressions.  The description below applies to normal evaluation,
       except where otherwise specified.

       field n
              The n-th part of field.  If n is omitted, it defaults to 1.

              The characters in string literally.

       @      All the authors joined as specified by the 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 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 i-th author of
              some reference is considered to be ambiguous if there is some
              other reference, such that the first i-1 authors of the
              references are the same, the i-th authors are not the same, but
              the 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 et-al command; this command may also
              specify additional requirements that must be met before an
              initial subsequence can be used.  @ tentatively evaluates to a
              canonical representation of the authors, such that authors that
              compare equally for sorting purpose will have the same

       %I     The serial number of the reference formatted according to the
              character following the %.  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.

       expr*  If there is another reference with the same tentative label as
              this reference, then expr, otherwise an empty string.  It
              tentatively evaluates to an empty string.

       expr-n The first (+) or last (-) n upper or lower case letters or
              digits of expr.  Troff special characters (such as \('a) count
              as a single letter.  Accent strings are retained but do not
              count towards the total.

       expr.l expr converted to lowercase.

       expr.u expr converted to uppercase.

       expr.c expr converted to caps and small caps.

       expr.r expr reversed so that the last name is first.

       expr.a expr with first names abbreviated.  Note that fields specified
              in the abbreviate command are abbreviated before any labels are
              evaluated.  Thus .a is useful only when you want a field to be
              abbreviated in a label but not in a reference.

       expr.y The year part of expr.

              The part of expr before the year, or the whole of expr if it
              does not contain a year.

              The part of expr after the year, or an empty string if expr does
              not contain a year.

       expr.n The last name part of expr.

              expr1 except that if the last character of expr1 is - then it
              will be replaced by expr2.

       expr1 expr2
              The concatenation of expr1 and expr2.

              If expr1 is non-empty then expr1 otherwise expr2.

              If expr1 is non-empty then expr2 otherwise an empty string.

              If expr1 is non-empty then expr2 otherwise expr3.

       <expr> The label is in two parts, which are separated by 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
              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 short-label command.

       (expr) The same as expr.  Used for grouping.

       The above expressions are listed in order of precedence (highest
       first); & and | have the same precedence.

   Macro interface
       Each reference starts with a call to the macro ]-.  The string [F will
       be defined to be the label for this reference, unless the
       no-label-in-reference command has been given.  There then follows a
       series of string definitions, one for each field: string [X corresponds
       to field X.  The number register [P is set to 1 if the P field contains
       a range of pages.  The [T, [A and [O number registers are set to 1
       according as the T, A and O fields end with one of the characters .?!.
       The [E number register will be set to 1 if the [E string contains more
       than one name.  The reference is followed by a call to the ][ macro.
       The first argument to this macro gives a number representing the type
       of the reference.  If a reference contains a J field, it will be
       classified as type 1, otherwise if it contains a B field, it will
       type 3, otherwise if it contains a G or R field it will be type 4,
       otherwise if contains a I field it will be type 2, otherwise it will be
       type 0.  The second argument is a symbolic name for the type: other,
       journal-article, book, article-in-book or tech-report.  Groups of
       references that have been accumulated or are produced by the
       bibliography command are preceded by a call to the ]< macro and
       followed by a call to the ]> macro.

              Default database.

       file.i Index files.

       REFER  If set, overrides the default database.

       indxbib(1), lookbib(1), lkbib(1)

       In label expressions, <> expressions are ignored inside .char

Groff Version 1.19.2           September 4, 2005                      REFER(1)