Template:Lessthan/doc

This template is for rendering a specific character "<", not for actually performing math operations. For that, you want ParserFunctions.

This template can be used in place of a literal "<" when the latter would be interpreted as a syntactic marker. In particular, it can be used inside templates meant for subst:ing, together with the  trick, to allow the subst:ed output to contain HTML comments that contain other subst:ed templates, parser functions or variables. This works even under the new parser, which doesn't otherwise allow code within comments to be evaluated.

For example, the code " " in a template produces " " when subst:ed.