mdrefine

style/emphasis ​

Writes emphasis with one marker, _ by default.

Style rule, fixed by format. Presets: recommended (warn). Dialects: all. Options: marker.

Before:

markdown
Use *emphasis* sparingly, as in un*believ*able.

After:

markdown
Use _emphasis_ sparingly, as in un*believ*able.

marker is "_" (the default), "*", or "consistent". With "consistent", the first parsed emphasis in the document chooses the marker, including emphasis inside a word, so a document starting with un*believ*able uses * for later emphasis too, and *first* and _later_ becomes *first* and *later*. Each document chooses independently, including when the first node cannot safely change. Code, HTML blocks, and Obsidian wikilinks do not choose a marker.

Edge cases and advanced usage ​

Details: with _, emphasis inside a word keeps *, because _ cannot mark emphasis there.

Left as written: markers where new ones could change how the text parses, and the exceptions of Forgejo and Gitea:

  • A new marker that would touch another * or _, or be separated from one only by ~.
  • Text with a * or _ that did not pair, as in *a _b* c_, or with a run of markers that two emphases share, as in *****a***. There markers change only where the rule can tell that every pair stays the same.
  • The text of a collapsed or shortcut reference, such as [*Title*][] or [*Title*], which is also its label, and text in brackets that would match a definition's label with the new markers.
  • A marker right after a $ on GitHub, Forgejo, and Gitea, where a _ after the dollar decides whether dollar math ends there.
  • Emphasis or strong text crossing an HTML region protected in Obsidian, or a block HTML/component line in VitePress. Delimiters on opposite sides do not form an editable pair in those readings. Independent pairs remain editable.
  • Emphasis that begins on the line of an alert's or a callout's marker and ends below it.
  • Emphasis whose text holds a run of tildes that could mark strikethrough, one or two tildes or in Obsidian two, while the paragraph holds another: GitHub can read strikethrough there and the markers as text.
  • A _, old or new, that only tildes separate from a letter or digit, as in x~~_b_~~, which GitHub reads as inside a word.
  • Text whose markers CommonMark pairs otherwise than the parser, as in xab***a* a*y: GitHub follows CommonMark, so the parser misread the text.

Dialect notes ​

In Obsidian: a paragraph, heading, or table cell whose text holds a * or _ that is not a marker, as in snake_case or 5 * 3, keeps its markers. Obsidian's Reading view pairs such a character with a later one, so snake_case and _em_ shows case and _em as emphasis, and snake_case and *em* is right only with the * kept. Escaped characters and those in code, math, or wikilinks do not count.