In normal topic text, expands to <nop>, which prevents expansion of adjacent macros and wikiwords
When the topic containing this is used as a template for another topic, it is removed.
%NOP{...}%deprecated
In normal topic text, expands to whatever is in the curly braces (if anything).
This is deprecated. Do not use it. Use %STARTSECTION{type="templateonly"}% .. %ENDSECTION{type="templateonly"}% instead (see TemplateTopics for more details).