pandoc-lua-filters/text-crossrefs/README.md

title, author, date

title	author	date
text-crossrefs: cross-references to arbitrary portions of text in Pandoc	Bastien Dumont (`bastien.dumont [at] posteo.net`)	2025/12/21

This filter extends Pandoc's cross-referencing abilities with references to any portion of text by its page number, its note number (when applicable) or an arbitrary reference type (with ConTeXt or LaTeX output). It currently supports the following output formats:

• context
• docx
• latex
• odt
• opendocument
• typst

Format-specific preliminary notices

DOCX and ODT/Opendocument

When opening for the first time a file produced by Pandoc with text-crossrefs, you should have to refresh the fields in order to get the correct values. In LibreOffice, press F9; in Word, a dialog box should appear when the file opens.

ConTeXt specifically

Your template should include the following directive before \starttext (as in the default template for ConTeXt):

$for(header-includes)$
$header-includes$
$endfor$

All TeX-based formats

All references are wrapped in a macro named \crossrefenum. It has two optional arguments: the first one is the reference type, the second indicates whether the prefix (e.g. “p. ”) should be printed or not (can be set to withprefix, noprefix, yes or no). The default values for these arguments should match those of tcrf-default-reftype and tcrf-default-prefixref (resp. page and yes, i.e. withprefix). The mandatory argument of \crossrefenum is a list of references (possibly ranges).

Here are some valid invocations:

• \crossrefenum[note][withprefix]{lblone, lbltwo, lblthree}
• \crossrefenum[page][noprefix]{lblone, lbltwo, lblthree}
• \crossrefenum[noprefix]{lblone, lbltwo, lblthree} (the first argument defaults to page)
• \crossrefenum{lblone, lbltwo, lblthree} (the second argument defaults to withprefix)
• \crossrefenum{only-one}
• \crossrefenum{lblone to lbltwo, lblthree} (the first reference points to a range)

For users from before December 2025: the formatting of the main argument of \crossrefenum changed.

It is up to you to define \crossrefenum in your preamble. If your target format is LaTeX, it should be possible to define it as a wrapper for the \zcref macro provided by the zref-clever package. Alternatively, you can use my implementation, which currently supports ConTeXt and LaTeX. Here are some hints about the implementation of the \crossrefenum macro:

• [The \crossrefenum macro is supposed to output non only the numbers, but also the prefixes and delimiters (e.g. “p. ” and “–”)]{#prefixes-tex};

• In ConTeXt, there is no way to retrieve the note number from a \reference or a \pagereference contained in the note as one would from a \label in LaTeX. To work around this, footnotes are labelled automatically with note: followed by the first identifier attached to a span in the note. Contrary to the ConTeXt syntax, this label is placed after the footnote content, so the \footnote macro has to be redefined. If your template includes the header-includes metadata variable like the default one does, this redefinition will happen automatically. Otherwise, you can copy-paste the following code in your preamble:

  \catcode`\@=11
  \let\origfootnote\footnote
  \def\footnote#1#2{
    \def\crfnm@secondArg{#2}%
    \ifx\crfnm@secondArg\crfnm@bracket
      \def\crfnm@todo{\crfnm@footnote@withlabel{#1}#2} %
    \else
      \def\crfnm@todo{\origfootnote{#1}#2}%
    \fi
    \crfnm@todo
  }
  \def\crfnm@bracket{[}
  \def\crfnm@footnote@withlabel#1[#2]{\origfootnote[#2]{#1}}
  \catcode`\@=13
  
  

Typst

You can either get an equivalent of \crossrefenum in Typst, the implementation of which is to be provided in your document, or simply output consecutive #ref commands. The advantage of the first approach is that a #crossrefenum command could handle a list of references intelligently (e.g. printing “pp. 1–3 and 5” instead of “pp. 1, 2, 3, 5 and 5”; see my implementation in TeX for more examples). The main drawback is that is has still to be implemented in Typst to date (14 December 2025), which is why text-crossrefs uses the second approach by default.

The #crossrefenum command has the following parameters:

crossrefenum(
  form: str,
  prefixed: bool,
  array dictionary label,
) -> content

form: "normal", "page", "pagenote", or an accepted type

prefixed: whether to print the prefix (e.g. “p. ”)

main argument: a label, a range, or an array of labels and ranges; ranges are dictionaries of the form (beg: <label1>, end: <label2>)

To see examples, please convert sample.md to Typst using this filter.

See the Typst-specific options to know how to switch to #crossrefenum. If you keep the defaults (outputting #ref commands), you may wish to set some formatting options. text-crossrefs will automatically add the following rule at the end of the preamble to prevent Typst from typesetting the prefix “page ” in addition to those that the filter already inserts:

#set page(supplement: [])

The filter also adds a show rule for #ref that prints the footnote reference number in normal script (by default, Typst handles it as a footnote anchor). If you wish to provide your own rules instead, you can set the metadata variable tcrf-typst-adaptations to false.

In the default mode, you can also (ab)use the note reference type to refer to a heading, figure or equation by its number, for the note reference type is mapped to the normal form in Typst, which is common to all these elements: for instance, [my-lbl]{.tcrf reftype=note} will be translated as #ref(<my-lbl>, form: "normal"), which may be printed as “Section 2” if my-lbl is a label attached to a section heading.

Usage

Basics

Mark the span of text you want to refer to later with an identifier composed of alphanumeric characters, periods, colons, underscores or hyphens:

Émile Gaboriau published [_L'Affaire Lerouge_ in
1866]{#publication}.[^1]

[^1]: It is a very [fine piece of literature]{#my-evaluation}.

[It was very popular.]{#reception}

To refer to it, write another span with class tcrf containing the target's identifier. If the span you are referring to is part of a footnote, you can refer to it either by page or note number according to the value of the reftype attribute (defaults to page). For instance, this:

See [publication]{.tcrf} for the publication date.
I gave my opinion in [my-evaluation]{.tcrf reftype=note},
[my-evaluation]{.tcrf}.

will be rendered in ConTeXt or LaTeX output as:

See \crossrefenum{{publication}} for the publication date.
I expressed my thoughts about it in
\crossrefenum[note]{my-evaluation}, \crossrefenum{my-evaluation}.

If you want to give a reference by note and page number like in the example above, you can also use the following shorthand:

[my-evaluation]{.tcrf reftype=pagenote}

In fact, you can use any identifier, including those automatically set by Pandoc.

To suppress the prefixes (e.g. “p. ”), you can set the prefixref attribute to no (defaults to yes). It can be useful, for instance, for small manually formatted indexes¹ :

Gaboriau:
[publication, my-evaluation, reception]{.tcrf prefixref=no}

Controlling where the label is placed

By default, most of Pandoc's writers place the labels at the beginning of the span they identify (the Typst writer is an exception). You can control the placement via the attribute refanchor, which can be set to:

• beg;
• end;
• both.

When the value is both, text-crossrefs creates two labels by suffixing -beg and -end to the identifier. The unsuffixed label remains usable except in Typst. A typical use case is:

[A portion of text that may cross a page break.]{#mylbl refanchor=both}

See [mylbl-beg>mylbl-end]{.tcrf}.

Page ranges

You can refer to a page range like this:

If you want to know more about _L'Affaire Lerouge_,
see [publication>reception]{.tcrf}.

The separator (here >) can be set to any string of characters other than alphanumeric, period, colon, underscore, hyphen and space (see the customization options).

In LaTeX and ConTeXt output, the above-mentionned \crossrefenum macro should be defined so that the range is printed as a simple page reference if the page numbers are identical. The syntax of a range is² :

\crossrefenum{{publication to reception}}

In DOCX and ODT/Opendocument output and in the default Typst output, a range will be printed as a range even if the numbers are identical.

Enumerations

You can enumerate several references as a comma-delimited list, for instance:

[ref-one, ref-two>ref-three, ref-four]{.tcrf}

In DOCX and ODT/Opendocument output, all these references will be printed, potentially resulting in unnecessary repetitions. In TeX-based output formats, they will be wrapped in \crossrefenum like this and should be collapsed by the macro when it is desirable:

\crossrefenum{ref-one, ref-two to ref-three, ref-four}

Customization

Most of the customization variables expect a string. In this case, all Markdown markup will be ignored. To prevent leading and trailing spaces to be stripped by Pandoc, they must be replaced with HTML entities ( ): see sample-with-options.md for examples.

Common options

The following metadata fields can be set:

• tcrf-references-enum-separator:
  • the string between two references in an enumeration in a reference span;
  • defaults to a comma followed by a space.
• tcrf-references-range-separator:
  • the string used to separate two references in a reference span;
  • defaults to >.
• tcrf-only-explicit-labels:
  • set it to true if you want crossrefenum to refer to spans with class label only;
  • defaults to false, can be set to true or yes (without quotes).
• tcrf-default-prefixref:
  • default value for the prefixref attribute;
  • defaults to yes, can be set to no or false (without quotes).
• tcrf-default-reftype:
  • default value for the reftype attribute;
  • defaults to page.

Options specific to DOCX, ODT/Opendocument and (by default) Typst

Here are some metadata fields for the docx, odt and opendocument formats. They are also used for typst unless tcrf-typst-crossrefenum is set to true (see above why they are ignored in ConTeXt and LaTeX output):

• tcrf-page-prefix:
  • “page” prefix;
  • defaults to p. .
• tcrf-pages-prefix:
  • “pages” prefix;
  • defaults to pp. .
• tcrf-note-prefix:
  • “note” prefix;
  • defaults to n. .
• tcrf-notes-prefix:
  • “notes” prefix;
  • defaults to nn. .
• tcrf-pagenote-separator:
  • the separator between the enumerated references in the output file when reftype is set to pagenote;
  • defaults to a comma followed by a space.
• tcrf-pagenote-at-end:
  • the string printed at the end of a pagenote reference in the output file;
  • defaults to the empty string, but it can be used to achieve something like n. 3 (p. 5) (see the sample file).
• tcrf-pagenote-factorize-first-prefix-in-enum:
  • defines if the prefixes of the type printed first in a reference to page and note should be repeated (like in “p. 6, n. 1 and p. 9, n. 3”) or set globally at the beginning of the enumeration (like in “pp. 6, n. 1 and 9, n. 3”);
  • defaults to no, can be set to yes or true (without quotes).
• tcrf-pagenote-first-type:
  • the type of the reference number that is printed first in references to page and note;
  • defaults to page, can be set to note.
• tcrf-range-separator:
  • the string separating the page numbers in a range;
  • defaults to –.
• tcrf-references-enum-separator:
  • the string separating the elements of an enumeration in a reference span;
  • defaults to a comma followed by a space.
• tcrf-multiple-delimiter:
  • the string between two elements (but the two last ones) in an enumeration;
  • defaults to a comma followed by a space.
• tcrf-multiple-before-last:
  • the string inserted between the two last elements in an enumeration;
  • defaults to and surrounded with spaces.

Options specific to the formats based on TeX

Since TeX is extensible, you may wish to support types other than page, note and pagenote for ConTeXt and LaTeX output. tcrf-additional-types can be provided with a list of supplementary accepted types, e.g.:

tcrf-additional-types:
- line
- figure

Once declared, these types can be used as the value of reftype in the same way as page, note and pagenote.

In addition, the following metadata field can be used to control the rendering of ranges of labels in \crossrefenum:

• tcrf-range-delim-crossrefenum:
  • the delimiter between the labels of a range in the TeX output file;
  • defaults to to surrounded with spaces.

Options specific to Typst

If the metadata field tcrf-typst-crossrefenum is set to true (defaults to false), text-crossrefs will output #crossrefenum commands modeled after the \crossrefenum macro for TeX-based formats (see above). The implementation of this command must be provided by the user. In this case, the metadata fields specific to TeX will be taken into account.

Otherwise, text-crossrefs will only output native #ref commands. In this case, the metadata fields specific to DOCX and ODT will be used. text-crossrefs adds two rules to header-includes to make #ref print only the reference numbers without formatting: if you prefer to define your own rules, set tcrf-typst-alter-ref to false.

Compatibility with other filters

As text-crossrefs and pandoc-crossref do not manage the same kind of cross-references, they can perfectly be used together.

text-crossrefs must be run after all filters that may create, delete or move footnotes, such as citeproc.

In a citation inside square brackets, the span bearing an identifier should not include a citation key, a locator or a ; delimiter. When it follows immediatly the locator, you should protect the locator with curly brackets. For example, this should work:

[@Jones1973, p. 5-70; @Doe2004[]{#jones-doe}]

[@Jones1973, p. 5-70; [it was elaborated upon]{#further-elaboration} by @Doe2004]

[@Jones1973, {p. 5-70}[]{#ref-to-jones}; @Doe2004]

not that:

[[@Jones1973, p. 5-70]{#ref-to-jones}; @Doe2004]

[[@Jones1973, p. 5-70; @Doe2004]{#jones-doe}]

[@Jones1973, p. 5-70[]{#ref-to-jones}; @Doe2004]

Breaking changes

Until December 2025, yes, no, true and false as metadata values had to be put within double quotes. Now, they must not be quoted at all, which is a more standard way to handle boolean values in YAML.

From December 2025, text-crossrefs formats [the main argument of \crossrefenum]{#breaking-comma-crfnm} as a comma-delimited list, not as a list of groups. This is in line the new, more readable formatting implemented in the version 1.2 of the crossrefenum TeX package.

License

Copyright 2024–2025 Bastien Dumont (bastien.dumont [at] posteo.net).

The program and all related files, including the present documentation, are under the MIT License: see LICENSE for more details.

---

1. About the comma-delimited syntax used in this example, see the section on enumerations below. ↩︎

2. Note that it can be customized. ↩︎