If it's a function for marking/identifying the origin of the emergency call, this is a very strange expression to use. If the origin of the call is Trondheim, or Tampere, Finland, any 'markering' can only be done by displaying the CLIP (Calling Line Identification Presentation), or the dialling number in plain language. The only 'markering' (flagging by way of colour or symbol) that would make any sense would be to identify the incomong call as an external or internal call.
I'm inclined to doubt that any of this is what's going on here, and suspect that it's a matter of hardware or software features carrying identification of origin, or in this case - mapping facilities showing identification of the mapper in question. Copyright Norsk Kartverk would be an example of such origin marking.

The term "opprinnelsesmarkering" is used "everywhere" in Norwegian as a term describing the caller ID service for phones (Google it ans see). I am convinced the same applies here.