== header ==
== header
!! header
h2. header

Using equal signs (=) is the most popular wiki header markup. Since there are more equal signs for smaller headers, subheaders will become more indented making it easier to get a visual overview from the markup alone. Closing equal signs are optional, making Creole more flexible since many wiki engines do not use them.

There was a complaint for exclamation points (!!) that they do not indent further headers, making it difficult to keep an overview of the document content. Also, stripping exclamation marks from the end can lead to a change of meaning.

Syntax like h2. looks too much like HTML.

Markup inside headings is not required, because the headings are already emphasised, so no bold or italic markup is required, they can't contain wiki markup, so nowiki markup is not needed, and the text from headings is often used as links in table of contents, or the headings themselves can be marked as links to themselves -- so link markup would conflict here.

== Headings in wiki engines

[{PieChartPlugin title='Headings in wiki engines'

equals before/after (less is bigger) (22), 22
exclamation points (11), 11
equals before/after (more is bigger) (3), 3
h1. header (3), 3
plus (2), 2

(22) Opening and closing equals (less is bigger) - GeboGebo, Giki, IkeWiki, JAMWiki, MediaWiki, miniWiki, MoinMoin, MoniWiki, Oddmuse, OpenWikiNG, PodWiki, ProWiki, ScrewTurn Wiki, SubWiki, UniWakka, UseMod, WackoWiki, Wala Wiki, WikiDoc, Wikispaces, WikyBlog, wxWikiServer

(11) Exclamation points (more is bigger) - ErfurtWiki, FlexWiki, PBWiki, PhpWiki, Pier, PmWiki, ProntoWiki, TiddlyWiki, Wiclear, Wikepage, yawiki

(3) Just opening equals - DidiWiki, KWikiKWiki, WikiASP

(3) Opening and closing equals (more is bigger) - DokuWiki, Qwik, WikkaWiki

(3) h1. - Clearspace, Confluence, StikiPad

(2) Plus - MicKI, Wikidot