Originally posted by Tygert
What does the "deselect" button on the clans homepage do?
Basically you 'deselect' a player, taken from your clan list, so that other clans will not include them in any potential challenge that they offer you. There's also a 'kick' option present to clan leaders, you won;t see that until a player makes himself unavailable for challenges. All members have 'player icons' next to their names, they tell you their status within the clan.
The icon descriptions are present below the player lists.