Preferred alternative for "externalID" - external_id, network_access_identifier, ...?

[hdamker]

Within issue #90 we have an open point about the preferred alternative for the developer non-friendly term externalId.

external_id would just introduce the needed snake_case to comply with the guidelines.
network_access_identifier would be the correct IETF term from RFC 4282, but maybe also too network centric.

Please add your rational and further proposals in the comments.

[hdamker]

The winner is "network_access_identifier". Thanks for your votes!