This is a container category — it doesn't hold articles directly. It exists purely to group together the individual year categories (such as Category:2004 establishments, Category:1965 establishments, and so on) that track when an organisation, publication, or other entity documented in the Vault was founded.
How this works
Each year-specific establishment category (e.g. Category:2004 establishments) is filed under this parent category. Individual articles should be added to the specific year category that matches their founding date, not to this page directly — for example, an article about a group founded in 2004 belongs in Category:2004 establishments, which in turn belongs here.
If an entity's founding year doesn't yet have a category, create one following the naming pattern Category:YYYY establishments, add [[Category:Establishments by year]] to it, and it will appear alongside the others below.
Related structure
The mirror category for closures is Category:Disestablishments by year, grouping the individual Category:YYYY disestablishments categories the same way. An entity that both opened and later closed will typically appear in one category from each family — for example, an organisation founded in 2004 and closed in 2007 sits in 2004 establishments and 2007 disestablishments individually, and both of those in turn sit under their respective by year parent category.