Help:HTML in wikitext

MediaWiki is able to parse some HTML tags in wikitext. Brackets for other tags are escaped and the tags are displayed instead of being parsed.

tag
The content of a tag is not parsed, as in a  tag.

You have to use the equivalent wikitext syntax to allow the content parsing. I.e. start each line with a blank space:

Some preformatted text which can contain wikitext, i.e. this idiomatic text will be parsed. Other line.