Text formatting

Strikethrough and small caps

The following formatting macros are used for strikethrough and small caps text:

[strike]#strike through text#
[smallcap]#small caps text#

Paragraph alignment

Paragraph alignment is defined as an attribute for paragraphs:

This paragraph is aligned left

This paragraph is aligned right

This paragraph is aligned center

This paragraph is justified, which is the default

Block quotes

As in normal Asciidoctor, block quotes are preceded with an author and a citation; but the citation is expected to be in the same format as all other citations, a cross-reference optionally followed by text, which may include the bibliographic sections referenced:

[quote, ISO, "ISO7301,section 1"]
This International Standard gives the minimum specifications for rice (_Oryza sativa_ L.)
which is subject to international trade. It is applicable to the following types: husked rice
and milled rice, parboiled or not, intended for direct human consumption. It is neither
applicable to other products derived from rice, nor to waxy rice (glutinous rice).


Notes that are not at the end of a clause are folded into the preceding block, if that block is not delimited (so that the user could not choose to include or exclude a note). That is, notes are folded into a preceding paragraph, list, formula, or figure.


Table and figure footnotes are treated differently from all other footnotes: they are rendered at the bottom of the table or figure, and they are numbered separately.


Ordered lists in both HTML and Word have their labels pre-configured to align with ISO/IEC DIR 2:

  • a), b), c) for the first level,

  • then 1), 2), 3) for the second level,

  • then i), ii), iii),

  • then A), B), C),

  • then I), II), III).

The type attribute for ordered lists in Asciidoctor, which allows the user to specify the label of an ordered list, is ignored.

List items with more than one paragraph

Asciidoctor and HTML support multiple paragraphs within a single list item (see list continuation). In HTML output, all the paragraphs within a list item will be aligned.

MS Word caveats
  • For list items containing multiple paragraphs, Metanorma attempts to format them appropriately by using custom list continuation styles (ListContLevel1 etc.); however, you should check the output document and may need to manually intervene.

  • In MS Word, each list entry must be a single paragraph. if the Asciidoctor contains more than one paragraph for a list item, the subsequent paragraphs will not be preceded by a bullet in Word, but they will also not be indented under the first paragraph of the list item.


While Asciidoctor tables are quite powerful for a non-XML markup language, they still have not dealt with the full range of complexity required in Metanorma.

Unlike Asciidoctor, Metanorma adds the option of multiple header rows via attribute “headerrows” to deal with the complexity of ISO tables requiring labels, variables, and units to lining up in the header. Tables can also have alternate text, to be rendered as a summary of the table for accessibility:

[headerrows=2,alt=Table of maximum mass fraction of defects in husked rice]
.2+|Defect 4+^| Maximum permissible mass fraction of defects in husked rice +
| in husked rice | in milled rice (non-glutinous) | in husked parboiled rice | in milled parboiled rice

| Extraneous matter: organic footnote:[Organic extraneous matter includes foreign seeds, husks, bran, parts of straw, etc.] | 1,0 | 0,5 | 1,0 | 0,5

Asciidoc allows table cells to have footnotes (which Metanorma renders inside the table) and notes following the table (which Metanorma moves inside the table footer).


Table 1 in the AsciiISO Rice example document illustrates a large range of table formatting options.

Mathematical expressions

Like Asciidoctor proper, Metanorma Asciidoctor accepts mathematical input in either LaTeX or AsciiMath, following the conventions of Asciidoctor:

  • The document attribute :stem: means any markup tagged as [stem] (\$...\$, or [stem] before a block delimited with ) is interpreted as AsciiMath.

  • The document attribute :stem: latexmath means any markup tagged as [stem] (\$...\$, or [stem] before a block delimited with ) is interpreted as LaTeX.

  • Any markup tagged as [asciimath] (\$...\$, or [asciimath] before a block delimited with ) is interpreted as AsciiMath.

  • Any markup tagged as [latexmath] (\(...\), or [latexmath] before a block delimited with ) is interpreted as LaTeX.

Any Unicode characters in the LaTeX source are translated into LaTeX escapes, through the unicode2latex gem.

In addition, stem markup that contains MathML markup (as detected by an initial <math …​ >) is interpreted as MathML.

MathML is used as the internal representation of STEM expressions in Metanorma: AsciiMath and LaTeX in Metanorma Asciidoctor are converted into MathML, using the asciimath gem and the latexmath processor of LaTeXML, respectively.

latexmath is much slower than other available LaTeX to MathML converters, but is also more accurate.
The syntax of AsciiMath recognised by the asciimath gem is more strict than the common MathJax processor of AsciiMath. (We have found that asciimath insists on numerators being bracketed.)


Formulae are marked up as [stem] blocks. Any explanation of symbols in the formula is given as a "where" paragraph, followed by a definition list.

For example:

w = (m_D) / (m_s)


stem:[w]:: is the mass fraction of grains with a particular defect in the test sample;
stem:[m_D]:: is the mass, in grams, of grains with that defect;
stem:[m_S]:: is the mass, in grams, of the test sample.


Like formulae, figures can be followed by a definition list for the variables used in the figure; the definition list is preceded by *Key*. For example:

.Typical gelatinization curve
footnote:[The time stem:[t_90] was estimated to be 18,2 min for this example.]


stem:[w]:: mass fraction of gelatinized kernels, expressed in per cent
stem:[t]:: cooking time, expressed in minutes
stem:[t_90]:: time required to gelatinize 90 % of the kernels
P:: point of the curve corresponding to a cooking time of stem:[t_90]

NOTE: These results are based on a study carried out on three different types of kernel.


Subfigures (which appear in ISO formats, for example) are entered by including images in Asciidoctor examples.

.Stages of gelatinization
.Initial stages: No grains are fully gelatinized (ungelatinized starch granules are visible inside the kernels)

.Intermediate stages: Some fully gelatinized kernels are visible

.Final stages: All kernels are fully gelatinized


Image size

The value auto is accepted for image width and height attributes. It is only passed on to HTML output; if the output is to Word, both the width and height attributes are stripped from the image.


Filenames for extraction

Images, source code, and requirements can all be extracted out of the generated Metanorma XML downstream, by the metanorma -e command. By default, the filename for each extracted snippet is automatically generated. (Extraction only applies to data-uri encoded images, which no longer preserve their filename.)

The attribute filename on images, source code, and requirements gives the filename that any inline-encoded images, source code, and requirements should be exported to, if that is requested by downstream tools.


In this instance, the image is read in from logo.gif, but is converted in the XML output to a data-uri encoding. The encoding will have the filename attribute of "image1.gif"; that instructs any downstream processing that extracts images out of the file (such as metanorma -e) to extract this image to the file image1.gif, instead of using an automatically generated filename.


All figures, tables, examples, formulas, permissions, recommendations and requirements ("assets") are autonumbered by Metanorma, so users do not need to specify any numbering in their source documents. The conventions for numbering vary by Metanorma flavour, but the default is to number all assets consecutively in the main body of a document, and separately in each Annex/Appendix, prefixed bt the Annex/Appendix number.

Rarely an asset needs to be excluded from autonumbering. This is indicated by giving it the option attribute %unnumbered:

.Typical gelatinization curve


The guidance given in ISO/IEC DIR 2 for internal cross-references guarantees unambiguous referencing and is followed rigorously by Metanorma.

In particular, if a formula, example, figure, list, list item or table is cross-referenced outside its (sub)clause, the clause containing the item is always given in the cross-reference, unless the item is being referenced in the same clause.

In the case of notes, the containing clause is extended to containing example, figure or table.


For example, in the AsciiISO Rice model sample document formula B.1 is defined in Annex B.6, and is referenced in B.6 and B.7.

In the Rice model document published by ISO, both instances are cited as "Formula (B.1)". However, Metanorma follows ISO/IEC DIR 2 in citing the former as "Formula (B.1)", but the latter as "B.6, Formula (B.1)".

In this sense, Metanorma is "more royalist than the king" in applying formatting rules and validation—which is what you would want of a computer-based tool.

The label of the item cross-referenced, the use of brackets, and the containing reference are all taken care of by Metanorma; the document author needs only give the item identifier in the Asciidoctor source (e.g. <<formulaB-1>> generates either "Formula (B.1)" or "B.6, Formula (B.1)", depending on where in the document it occurs.)


Normally in Asciidoctor, any text in a cross-reference that follows a comma constitutes custom text for the cross-reference. So a cross-reference the foregoing reference would be rendered as "the foregoing reference", and hyperlinked to the ISO7301 reference.

In Metanorma Asciidoctor cross-references, bibliographic localities (e.g. page numbers, clause numbers) can be added directly after the comma, as part of the cross-reference text. This overrides the normal Asciidoctor treatment of custom text.

List items

List items can be cross-referenced by inserting a bookmark at the very start of the list item:

. Ordered list
.. [[id]] This is the first list item
... [[id]] This is a list sub-item

Hyperlinks to URIs can have alt text, which is used in accessibility (corresponding to the HTML a@title attribute). This is specified by appending ",title=…​" after the text in the URL macro in Asciidoctor:

http://www.example.com[text to go into the hyperlink]

http://www.example2.com[text to go into the second hyperlink,title=This is a tooltip for the link]

Cross-references to external documents

Metanorma will process cross-references to anchors within external documents just like Asciidoctor would normally. For example,


will be processed as a link to anchor #b in document document1.adoc.

If the reference uses the .adoc suffix, as in the example above, it is stripped in Metanorma XML and substituted with the extension of the current document type during document generation.

The above example is rendered in Metanorma XML as <xref target="document1#b">, in HTML as <a href="document1.html#b">, and in PDF as <a href="document1.pdf#b">.