Account deletions and Names

So recently Ive been on the hunt for a new name. I think and think and think, and then i hit one that i love. I look it up, not available. Damn. I search it in client? No match history, hasnt played since the mastery system was released, and is level 2....

So are their guidelines that Riot has for purging inactive accounts of any kind? If so what are they, if not why not?