Clash-of-clans – How to ban a person from your clan

I think that is based in your troop level and heroes but Supercell only says:

During battle day, you will always have a recommended target visible on the war map. The recommended target shows you the closest match for your attack strength based on the defense strength of your opponents. Base layout isn’t taken into consideration, though, nor is your favorite attacking style, so it is a good idea to also check a few bases above it and a few bases below it to see if you can find a target you like better.

If someone in your clan asks for "Level 5 Hogs" in a language you don't understand you wont be able to help them and you may give them what they DO NOT want. In war it is very important to give the troops asked for because war strategies are chosen in advance. Giving the wrong troop results in additional troop request delays.

In our clan we not only require English, but that the player names also be in the Latin alphabet. I cannot read or write in Mandarin, so how would I address or communicate to a player with Chinese characters in his name?

Finally, for a war clan, it's not just language that matters... being in a similar timezone is very helpful. If you are asleep while the rest of your clan is planning and attacking and v.v. you will not be much help or receive much help.