xkaraman left a comment (kamailio/kamailio#4336)
Hmm interesting Following https://datatracker.ietf.org/doc/html/rfc8141#section-2 which is a generic URN RFC i imagine, the `@` character is allowed as part of `pchar` defined in [RFC 3986 ](https://datatracker.ietf.org/doc/html/rfc3986).
Now about service URNs seems to not follow this RFC, or i might misread something, or something i don't fully understand.