It has wide acceptance among editors and is considered a standard that everyone should follow. Except for minor edits, please make use of the discussion page to propose changes to this policy.
Wikimedia Commons is a multilingual project. This page contains the project's policy on how multilingual content is used, and what content should be in which language.
Descriptions at galleries, categories and file description pages can be in any language and should be added in multiple languages. The use of language templates is encouraged to reduce the amount of unnecessary information and visual clutter.
Gallery names should generally be in the local language. See Commons:Galleries for the exact policy.
Category names should generally be in English, excepting some of proper names, biological taxa and terms which don't have an exact English equivalent. See Commons:Categories for the exact policy. See also the proposal of Naming categories.
Creator names should be in form most commonly found in English literature.
Files can be named in any language. The name of the file should be descriptive. See Commons:File naming for the exact policy.
Templates can be made in any language. When the text of a template is available in multiple languages, the English version is the authoritative version on which other language versions of the template should be based.
Policies and guidelines should be written in English and translated to other languages. The English version of the policy or guideline is the authoritative version on which other language versions should be based.