"nationals" (essentially, Canadians), 20 "internationals" (almost exclusively Americans), and 3 quarterbacks. The traditional NFL football season runs from the 2nd week of September until late December or the start of January, with the NFL playoffs occurring in January and February. In contrast, the CFL regular season runs from late June to late October. This is in order to ensure the Grey Cup playoffs can be completed in mid-November, before the harsh Canadian winters set in. This is an important consideration for a sport played in outdoor venues in locations such as Regina, Edmonton and Winnipeg. In American football, officials typically use yellow penalty flags, while coaches' challenge flags are red. Before the 2022 CFL season, officials' penalty flags used in the CFL were orange in color, and challenge flags were yellow. Since then the CFL has adopted the NFL's flag colours. In American leagues, the referee wears a solid white cap, and the other officials wear black with white piping. Until 2018 in the CFL, the referee wore a black cap with white piping, and the other officials wore white caps with black piping; starting with the 2019 season, the referee now wears a white cap with black piping, and the other officials wear black ones with white piping, almost mirroring the American convention (and matching the standard for the lower levels of the game in Canada). Additionally, when announcing penalties, in American football, the penalized team is announced using generic terms ("offense"/"defense", for example), but in Canadian football (especially the CFL) the penalized team is announced by their respective city or province. The CFL regular season comprises 18 games since 1986, with the exception of 2021, in which a 14-game schedule was used, while the NFL regular season has consisted of 17 games since 2021. There are several radical differences concerning how the leagues calculate regular season records and how ties in the standings are broken: The CFL awards two points for a win, one point for a tie and zero points for a loss (from 2000 to 2002 inclusive, the CFL also awarded one point for an overtime loss). The CFL ranking system is in keeping with the traditional system in most other football codes of British origin, and is also the basis for the system used in hockey. The NFL by contrast officially ranks its teams strictly by winning percentage, with ties counting as a "half-win" for