Note that the original tdoc need not be a tdoc to the same meeting, but could be from any previous meeting of the group - or indeed, from any other 3GPP group, as long as 3GU can identify it. Note that if you choose to revise a tdoc from a previous meeting, you will have to take care that the decision on the original tdoc was not final. For example, if the original tdoc was a CR, then its status would ideally have been "postponed", allowing decision in a later meeting. In any case, it is not permitted to revise at working group leven a CR tdoc which has already been definitively concluded at TSG level: that is, already bears a TSG status of "approved" or "rejected". In such a case, a brand new tdoc must be created, not a revision of the original. Expect your MCC project manager to police this rule.