This directive can be used to declare that an HTML rendering
rule takes HTML content as argument. It has two effects. It
emits the appropriate meta_predicate/1 and instructs the
built-in editor (PceEmacs) to provide proper colouring for the
arguments. The arguments in Head are the same as for
meta_predicate or can be constant html
. For example:
:- html_meta
page(html,html,?,?).