Help:Magic words

Magic words are functions in MediaWiki that either modify the page and are called with double underscores on each side (officially referred to as "behavior switches") and things that return information and are called similarly to templates (officially referred to as "variables", ones that can take parameters can also be called "parser functions"). This is a list of helpful magic words and descriptions. Functions marked as red use more server resources and should not be used unless neccesary. Behavior switches are typically used directly on pages (although can be used on templates, such as  on Not unused, and variables and parser functions are typically used on templates. Variables and parser functions can also be substituted by putting   before the name of it but after the opening braces. This is also not a comprehensive list, and only includes the ones that are simpler and/or more likely to be used here. For a full list and more in-depth explanations, see the mediawiki.org documentation.

Variables
All time-related variables use UTC and may not be fully accurate due to server-side caching.