Template to show HTML as plain text
Fragment of a discussion from Project:Support desk
Its not all that commonly used, I'm not sure if it has a name - but its documented on help:Magic Words (near the bottom). But basically any <tag-name> type extension, can also be called using {{#tag:tag-name|...}} syntax. The difference is, that in the <tag-name>...</tag-name> version, no wikitext is expanded (by default anyways, the extension itself can expand wikitext if it wants, for example <ref>...</ref> does, although pre-save-transform is never done), but when it is called as {{#tag:tag-name|...}} {{{1}}}'s, templates, and parser funcs are expanded, and pre-save-transform (converting ~~~~ to signature's, pipe-trick, and subst:) is done.
