Currently when creating or forking a repository the URL slug for the repository is generated automatically. When the repository name has a "special" character such as ä, ö, å and so on, it gets simply converted to a dash (-).
For repository names that have many of these characters the semantic meaning of the repository URL slug is lost. For example "Yömyöhässä" becomes "y-my-h-ss-" (instead of "yomyohassa"), which by itself is not of use and might confuse people about what the resource actually represents.
This is not limited to ä, ö or å. Other special characters, that might be used in daily written languages in some languages, should be properly converted. These three letters in my example are quite vital for northern european languages.
(At least I could not find an option to change the generated URL slug to a different value.)