NOTAM – A Notice to Airmen. A notice distributed by means of telecommunications containing information concerning the
establishment, conditions or change in any aeronautical facility, service, procedure or hazard, the timely
knowledge of which is essential to personnel concerned with flight operations.

NOTAMs are often required as part of a UAV SFOC when flying in controlled airspace.

For checking for NOTAMs in your area, the official source in Canada is NAV Canada: https://flightplanning.navcanada.ca
Another great more interactive visual resource for NOTAMs is Zulu for Pilots: http://www.zuluforpilots.com/Map

Canadian NOTAM Procedures Manual

The purpose of this manual is to provide information, guidance and standard procedures for the
origination, distribution and query of NOTAM in Canada. This manual is intended for reference and usage
by NAV CANADA personnel, and accountable sources and originators not within NAV CANADA

Wikipedia – NOTAM