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| 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*stringmn | 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 behavior is et-al " et al" 2 3. |
| includefilename | Include filename and interpret the contents as commands. |
| join-authorsstring1 | This says how authors should be joined together. When there are exactly two |
| string2string3 | 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. | |
| label-in-reference* | When outputting the reference, define the string [F to be the reference's label. This is the default behavior; so the negative version of this command is more useful. |
| label-in-text* | 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 behavior; so the negative version of this command is more useful. |
| labelstring | string is a label expression describing how to label each reference. |
| separate-label-second-parts | When merging two-part labels, separate the second part of the second label from the |
| string | first label with string. See the description of the <> label expression. |
| move-punctuation* | 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 that 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 ignored. |
| 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-adjacent-labels* | 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. |
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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 following description applies to normal evaluation, except where otherwise specified.
| field, field n | The nth part of field. If n is omitted, it defaults to 1. |
| `string' | 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 that 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 representation. |
| %n, %a, %A, %i, %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, expr_n | The first (+) or last (_) n uppercase or lowercase letters or digits of expr. troff special characters (such as \(`a) count as a single letter. Accent strings are retained but do not count toward 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. |
| expr.+y | The part of expr before the year, or the whole of expr if it does not contain a year. |
| expr._y | 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. |
| expr1expr2 | 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. |
| expr1|expr2 | If expr1 is nonempty, then expr1; otherwise, expr2. |
| expr1&expr2 | If expr1 is nonempty, then expr2; otherwise, an empty string. |
| expr1?expr2:expr3 | If expr1 is nonempty, then expr2; otherwise, expr3. |
| <expr> | The label is in two parts, which are separated by expr. Two adjacent two-part labels that 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 |