未分类的英文：
UC ; UnClassified ; unclassified ; unsorted

unclassified mail.
未分类的邮件

Pertaining to a signal or area which contains either encrypted classified or unclassified information.
用于修饰或说明包含加密的保密或不保密信息的信号或区域。

This is sometimes called "unclassified," "probational," or "provisional" admission
这个条件有时叫做“不分类入学”，或“试予入学”，或“暂时入学”。