Pages that share the same name are called twins. Federated wiki offers several affordances that helps one acknowledge twins and move freely between them.
Pages are judged to have the same name if their title compresses to the same slug. Slugs are the names used in urls and as keys in databases.
A site has at most one page for any given name. But since we browse multiple sites at once we will often encounter twins for pages. Here is how.
A link will go to the 'closest' twin.
A reference flag will go to a specific twin.
A page will show twins in the space above its title.
A title in Recent Changes lists twins of that page.
Two pages with the same name from different sites. Each page signals the existence of two other twins, some newer, others older.
Links and references are predictable in that they will always look in the same sites for a page based on information it finds surrounding the links without looking past the current page. That makes clicking links repeatable.
Twins shown atop pages and in Recent Changes come from the growing neighborhood that one has been browsing. Should new twins be discovered, the lists of twins will be updated immediately.