Could it have been "mss?" "Ms" is an abbreviation for "manuscript." "Mss" can be an abbreviation for the plural, "manuscripts." "Manuscript" literally means "handwritten." The "manuscript" is the form in which an author submits something to a publisher, before it is accepted and typeset into book form. One can imagine an literary agent saying "I'm very busy, I have a lot of mss. to get through."

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