The stabdard differs across different counties.
It works like this in Derry as Far as I know
Senior Championship
Senior Reserve Championship (Senior Football Club's B Team)
Intermediate
Intermediate Reserve Championship (Intermediate Club's B Team)
Junior Championship
3rds Championship (Any club that can field a 3rd team are here although they used to play in the Junior C'ship and I think most play in the Junior league anyway)
It works like this in Derry as Far as I know
Senior Championship
Senior Reserve Championship (Senior Football Club's B Team)
Intermediate
Intermediate Reserve Championship (Intermediate Club's B Team)
Junior Championship
3rds Championship (Any club that can field a 3rd team are here although they used to play in the Junior C'ship and I think most play in the Junior league anyway)