The MoSCoW method is a prioritization technique on which each non-O letter refers to the priority of each requirement (Must have, Should have, Could have, and Would like but won't get). Some RFPs will use this method to state clearly what the proposals shall have, what is a nice to have, what is optional and what could be left for further versions of the information system to be delivered).
For more information: https://en.wikipedia.org/wiki/MoSCoW_method
