There is no commonly accepted standard wikitext language. The grammar, structure, features, keywords and so on are dependent on the particular wiki software used on the particular website. For example, all wikitext markup languages have a simple way of hyperlinking to other pages within the site, but there are several different syntax conventions for these links. Many wikis, especially the earlier ones, use CamelCase to mark words that should be automatically linked. In some wikis (such as Wikipedia and other MediaWiki-based wikis) this convention was abandoned in favor of explicit link markup, which Wikipedia calls "free links", for example with [[…]].
Some Wiki programs allow extensive optional use of select HTML elements within wikitext, others a smaller subset, and still others no HTML at all. In some cases, restrictions on HTML may be wisely determined by each site that uses the program.
MediaWiki, the software that runs Wikipedia, has a wiki markup language that allows many common HTML tags; it is intended to provide an alternative syntax to allow some users to use it without knowing HTML.
See also Edit
<ref>tags exist, but no
<references/>tag was found