there needs to be some other mechanism for discovering twins
We convert link text to slugs and thus gain safe text for use in urls and flat file names. Slugs use all lowercase and thus provide case independent retrieval of pages. Once retrieved, the title's mixed case and special characters are rendered from the title field of the page json.
> Using a different approach will mean that a client probably should not generate the slug itself, but rather look it up in the sitemap file. The current client does not do this, so it is possible that wiki that have not been upgraded will not be able to see that content where the two schemes give a different slug. –– Paul. issue comment 
there needs to be some other mechanism for discovering twins
But what if we didn't just discover the twins, but created them?
See also Completion Rules. matrix
A step in this direction would be to implement a Survey Probe to demonstrate the utility of the concept. If you could compute an "invariant signature" that would be usefully the same in all translations then this would become an extension of the sitemap for participating sites. matrix
Yes, I (Ralf) am thinking of the creation of a probe for Paragraph Vectors. matrix
I (Ward) will write the Mech Block that does the invariant search taking this search as inspiration:
Inspiration
This search was reach through the "search" link in the page footer for the Check the Weather page. It searches the whole federation. Maybe the Mech Block should only search the neighborhood. That would be a lot faster and probably more aligned with the "twins" logic. matrix
SEARCH SLUGS discover-twins