Twins are pages from different sites that have the same or sufficiently similar names. Twins may or may not have a common origin.
The flags of known twins are shown a the top of each page.
Twin flags are organized in to groups based on the date of their most recent edit, older, newer and same.
A page that has been 'forked' from another site will be categorized as same until one or the other site makes a non-fork edit.
See Fork Button