Not sure if I understood it correctly, but this specification seems to discuss about SIP URI based non-mobile identities: https://www.gsma.com/futurenetworks/wp

Not sure if I understood it correctly, but this specification seems to discuss about SIP URI based non-mobile identities: https://www.gsma.com/futurenetworks/wp-content/uploads/2019/10/RCC.07-v11.0.pdf https://www.gsma.com/futurenetworks/wp-content/uploads/2019/...