This template is used to display a small flag icon next to a wikilinked country name. It is related to the {{flagicon}}, {{flagcountry}} and {{flagu}} templates, but offers more options in terms of the text string displayed.
{{flag|country identifier|optional variant|name=alternative text string|size=maximum width and/or height of the flag image}}
country identifier is the common name of the country (e.g. "United States"), a common alias (e.g. "US"), or a standard country code such as those listed at ISO 3166-1 alpha-3
variant is an optional second parameter that can be used to display a flag variation, such as a historical flag. The list of variants for each country is documented on the appropriate template page, such as Template:Country data Germany
alternative text string, this optional value, specified by the name parameter, is used to display alternative text
size, this optional value is specified by the size parameter, and is used to specify the maximum width and/or height of the flag image. This parameter is specified using standard image syntax.
See the prefix index for the templates latently called by this one.
Flags are also available for several sub-national and multi-national entities such as US states, Canadian provinces, and the European Union. A complete list can be found at Category:Country data templates.
The size parameter can be used to control the image dimensions. 23×15px is the default size for most countries (some entities have a different default size).