You don't even need to set that as the server name. As long as you are actually playing match while in Match mode, you're fine.
Let me see if I can give some examples of what is allowed and what isn't:
Coop mode in Sapphire Falls, yet ringslinger is on and everyone is fighting: Not allowed. The gametype is set as Coop, so you should be finishing levels. There is no exit in Sapphire Falls, so Coop is impossible here.
Match mode in Techno Hill Act 2, and everyone is shooting each other: Allowed. The gametype is Match, and everyone is playing match.
CTF in Meadow Match, everyone is shooting each other: Not allowed. There are no flags in Meadow Match, therefore CTF is impossible to do. If you want Team Match, set the gametype to Team Match.
Tag in Greenflower Act 2, playing Hide and Seek: Allowed. Hide and Seek is allowed as long as you are in the Tag gametype, as Tag and Hide and Seek are almost the same thing.
Coop in Thunder Citadel, playing Hide and Seek: Not allowed. Hide and Seek is not allowed in Coop mode, as Coop mode suggests that you are beating levels.
Let me see if I can give some examples of what is allowed and what isn't:
Coop mode in Sapphire Falls, yet ringslinger is on and everyone is fighting: Not allowed. The gametype is set as Coop, so you should be finishing levels. There is no exit in Sapphire Falls, so Coop is impossible here.
Match mode in Techno Hill Act 2, and everyone is shooting each other: Allowed. The gametype is Match, and everyone is playing match.
CTF in Meadow Match, everyone is shooting each other: Not allowed. There are no flags in Meadow Match, therefore CTF is impossible to do. If you want Team Match, set the gametype to Team Match.
Tag in Greenflower Act 2, playing Hide and Seek: Allowed. Hide and Seek is allowed as long as you are in the Tag gametype, as Tag and Hide and Seek are almost the same thing.
Coop in Thunder Citadel, playing Hide and Seek: Not allowed. Hide and Seek is not allowed in Coop mode, as Coop mode suggests that you are beating levels.