The
content argument of macros contains the "main content" of the macro, i.e. the textual content that will show the most proeminently once the macro is rendered. It is usually, but not always, the first positional argument of macros. We should probably make it into an official macro argument property at some point.In most cases, it is quite obvious which argument is the
content argument, e.g.:\imacro: in\i[asdf qwer]thenasdf qweris thecontentargument\amacro: in\a[https://example.com][example website]thenexample websiteis thecontentargument
Some macros however don't have a
content argument, especially when they don't show any textual acontent as their primary rendered output, e.g.:\Imagemacro: this macro hastitlebyt not content, e.g. as in:\Image[flower.jpg]{title=}, since the primary content is theImagerather than any specific text
Philosophically, the
content argument of a macro is analogous to the innerHTML of an HTML tag, as opposed to attributes such as href= and so on. The difference is that in OurBigBook Markup, every macro argument can contain child elements, while in HTML only the innerHTML, but not the attributes, can.