Extended CommonMark manual manual markdown zettelstore zmk 00001004020000 00001008010000 00001012920513 00001004020000 00001008010000 00001012920513 1 (c) 2020-present by Detlef Stern 00010101000000 00001002000000 00001008010500 00001008010801 00001008010802 00001008010803 en EUPL-1.2-or-later 20260701135717 00001008010500 20260701135717 public While CommonMark is a well-specified Markdown dialect, some useful elements are missing. To be precise, these elements are also missing from the original Markdown proposal. Therefore, Zettelstore allows its users to make a trade-off and provides a choice: use CommonMark for a Markdown syntax that will be useful in other Markdown-processing software, or use Extended CommonMark to make use of elements found in proprietary Markdown-processing software. The first choice focuses on the longevity of stored zettel, together with better compatibility with other tools. The second choice trades longevity for additional features beyond CommonMark. Extended CommonMark is a strict superset of CommonMark. Every element of CommonMark is also supported in Extended CommonMark. Currently, Extended CommonMark extends CommonMark with strikethrough and tables. Strikethrough One or two tilde characters (~, U+007E) mark deleted text. For example, abc ~~def~~ ghi ~jkl~ is rendered in HTML as: abc def ghi jkl. As with regular CommonMark emphasis delimiters, a new paragraph causes strikethrough parsing to stop. Three or more tildes do not create a strikethrough. Tables A table consists of a single header row, a delimiter row separating the header from the data, and zero or more data rows. Each row consists of cells containing arbitrary text in which inline elements are parsed, separated by vertical bar characters (|, U+007C). A leading and trailing vertical bar character is also recommended for clarity. Spaces between vertical bar characters and cell content are trimmed. The delimiter row consists of cells whose only content is hyphen-minus characters (-, U+002D), optionally preceded or followed by a colon character (:, U+003A), or both, to indicate left, right, or center column alignment. For example: | foo | bar | | --- | --- | | baz | bim | will be rendered in HTML as: foo bar baz bim To show the effect of an alignment specification: | foo | bar | baz | bim | | ------- | :--- | :-: | --: | | default | left | center | rightright | | one | twotwo | three | | alpha | beta | gamma | delta | epsilon | will be rendered in HTML as: foo bar baz bim default left center rightright one twotwo three alpha beta gamma delta