I do not think there is a legal term. What you should do is insert something like the following at the beginning: This document is a draft only, provided for your comments; it is not intended for distribution to the general public or press as its contents are provisional . What you can also do, and which may be more useful, is to put a full page watermark of the word "DRAFT" diagonally across every page - this makes it difficult to reproduce without it being obvious that it is a draft.
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