DokuWiki supports bold, italic, underlined and monospaced texts. Of course you can combine all these.

DokuWiki supports **bold**, //italic//, __underlined__ and ''monospaced'' texts.
Of course you can **__//''combine''//__** all these.

You can use _subscript and ^superscript, too.

You can use <sub>subscript</sub> and <sup>superscript</sup>, too.

You can mark something as deleted as well.

You can mark something as <del>deleted</del> as well.

Paragraphs are created from blank lines. If you want to force a newline without a paragraph, you can use two backslashes followed by a whitespace or the end of line.

This is some text with some linebreaks
Note that the two backslashes are only recognized at the end of a line
or followed by
a whitespace \\this happens without it.

This is some text with some linebreaks\\ Note that the
two backslashes are only recognized at the end of a line\\
or followed by\\ a whitespace \\this happens without it.

You should use forced newlines only if really needed.