Not many controllers away from the northern border of the U.S. are familiar with Canada’s alphabetic aircraft registration system and it can cause confusion.
C-ABCD: XXXX tower this Canadian Civil Charlie Alpha Bravo Charlie Delta. Request runway in use.
No response
C-ABCD: Again XXXX tower Canadian Civil Charlie Alpha Bravo Charlie Delta requesting runway in use.
No response
C-ABCD: Wichita tower,Canadian Civil Charlie Alpha Bravo Charlie Delta requesting runway in use.
XXXX Tower: Canadian alphabet soup aircraft calling XXXX tower please say again.
Pete Simpson