It's now possible to add an LXMF contact address to interface discovery data, using the discovery_lxmf_address option per interface. The intention of this is to make it easier for operators to get in contact with each other, coordinate network interconnections and local network expansion, or just get in touch with other local operators.
Would be good to have support for this field added to user-facing applications as well - still need to integrate it in Sideband myself ;) But at least, you can see it in the rnstatus -D output.