Markup

A markup block is a freeform text annotation written in Markdown. Markup blocks support basic text formatting and can embed traceable references to other entities in the specification.

A markup block appears in two positions:

• As the body of a requirement — placed after the is keyword, making the requirement informal (see Requirement).

• As a standalone annotation on any entity — placed before the entity keyword, it serves as freeform rationale or commentary.

Syntax

@@ <RICH_TEXT|REFERENCE>* @@

Example — annotation and informal requirement body

@@
  The **main propulsion unit** of the aircraft. See {System::Requirements::Thrust}
  for the associated constraints.
@@
part Engine
  let max_thrust in real [N]

  requirement ThrustBound is
    @@
      The {Engine::max_thrust} shall not exceed the structural limit
      at any operating altitude.
    @@
  requirement
part

Format

Rich Text

The body of a markup block is written in Markdown, conforming to the CommonMark specification.

Commonly used formatting elements include:

• Emphasis: *text* or _text_

• Strong: **text**

• Headings: # Heading

• Inline code: `` code ``

• Unordered list: - item

• Maths (LatEx): $ math $

Note

Not all CommonMark elements may be supported by every output format. Consult the tooling documentation for rendering details.

Reference

A reference embeds a traceable link to another entity directly within a markup block. The target is identified by its path (see Reference).

Syntax

{PATH}

Attention

Escape sequences for literal {, }, and @@ within a markup body are not yet specified. The characters { and } are currently reserved for references.