After reading various parts of the net, I must admit that there is not much information about this situation available, which possibly means that nothing should be said here (as jgoggi suggested), but in https://forums.vatsim.net/viewtopic.php?p=32980 I found "proceed as filed" and "proceed direct to (next waypoint name)".
dmarch wrote: Well I don't think we have anything else in the can to use in place of Resume own navigation
jgoggi wrote: - Never heard the departure controller giving QNH
- When on a SID it's absolutely incorrect to hear the departure controller say "resume own navigation", while it's correct after giving headings.
So maybe "continue as filed":
pfchat556=continue
pfchat558=as filed
Or "continue direct to (next waypoint name)":
pfchat556=continue
pfchat566=direct to
Further discussion about this:
http://www.pprune.org/archive/index.php/t-14771.html
http://www.pprune.org/archive/index.php/t-15721.html
Here people seem to agree that "Resume own navigation" should (or has to?) be followed by a "to XYZ" or "direct to XYZ" and only happens after being radar vectored, which I read as not after a SID.
So I would propose:
Find the next waypoint name.
If found:
- after vectoring (no SID), issue "Resume own navigation to XYZ"
- after a SID, issue "continue direct to XYZ"
If not found (can this happen? maybe on very short flight plans?):
- after vectoring (no SID), issue "Resume own navigation"
- after a SID, issue "continue as filed"