USA stations operating from Canada

A number of USA stations, mainly operating mobile, operate from Canada without indicating the country identifier in their callsign.
These stations do not comply with the terms of RBR-4, so QSOs with these stations are mapped as INVALID by Club Log.

"9.2 The operator of an amateur station licensed by the Government of
the United States shall identify the station:

a. by transmitting the call sign assigned to the licensee's
station by the Federal Communications Commission;

b. if transmitting:
by radiotelephony, by adding the word "mobile" or "portable", or
by radiotelegraphy, by adding an oblique character ("/"); and

c. by adding the Canadian amateur call sign prefix set out in
Column I of an item of Schedule IV for the geographical location of
the station set out in Column II of that item."

from http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf01226.html#operation

Thanks to Jim, AD1C.