From the RCA Standing Orders:
The Royal Canadian Artillery Standard is intended for ceremonial use only. It
is not carried on parade. It is not broken and shall be flown from flagpoles. The
occasions when it will be flown are at the discretion of artillery commanders, but in
general will be:
a. visits of royalty;
b. visits and inspections by the Colonel Commandant or artillery officers of brigadier-
general rank and above;
c. visits by the Director of Artillery;
d. visits of allied artillery officers of comparable rank;
e. visits and inspections by the Governor-General and by Lieutenant-Governors; and
f. regimental birthdays, St. Barbara’s Day, Artillery Day and Canada Day.
Today's Artillery Day. Thanks for wondering enough to ask ;D
Cheers.