[CQ-Contest] Un-hijack "disappointing experience" #1 -- partial calls

[Art Boyars]

Somebody already mentioned it, but "partial calls" in this case means the
runner extracts only part of a call from the mess, and sends, for example,
"DL2" or DL2?".  Proper response from the callers is for DL2-whoever to
come back ... and nobody else.  We'll cut some slack for DR2 or DL2, etc.,
particularly if no DL2 is heard.

However, HS0 is not allowed (that's just a random prefix for this example;
not to imply that any HS0's were guilty).

73, Art K3KU