A BA where I work instists on writing his requirements in a form where he uses the MoSCoW categorisations keywords within the requirement descriptions.  Hence the requirements all take the form of:

so for any requirement that he has categorised as M the requirement text will contain the word "must", any that are categorised as C will contain the word "could" etc. 

I have suggested to him that this is poor form.  In my view it renders the priority column redundant.  Re-prioritising the requirements means having to change the requirement description.  Particularly confusingly, any W priority requirements could potentially be read as a double negative.

In it's simplest form, I'd suggest to him rewriting the above as

Then the steps of writing the requirement and categorising it are not confused, requirements can be reprioritised without needing to edit the requirement description, and the annoying double negative is removed.  However, he insists that his way of doing it is correct.

My question is, is it accepted practice for BAs to write requirements in this style?  Am I being too picky in objecting to this, or am I correct that it is poor form?  And does anyone have a reference to any advice that would back up this argument one way or another?

Thanks.