To Bostonian ears if you say rota, I will think of an automobile part or the Sacred Rota as wwh mentioned, or the thing where you learn by rote (repeating) depending on context.... However, seeeing it written, I'd think of a formal agreement to do something...and where I "learned" the latter I'll never know! So now I know better ... an agreement to alternate performance of a task...Learn something new every day!