In general, your CV should reflect every halfway-recent show for which you've received credit, including any "Special Thanks" credit which you'd be comfortable enough discussing at a job interview. (i.e: If you got the Special Thanks for being married to the producer, then don't include it; if you got the Special Thanks for helping with a complex technical problem, or providing organizational support, or otherwise involving yourself in an infomal role, then include it on your CV.)
And there are very limited circumstances under which you might omit certain credits. For example, if you did a gig for the "Throbbing Loins Burlesque Showcase", you might omit this credit from a CV you send to a K-12 school or a church or a summer camp. But this is something you'd do for editorial reasons, rather than to save space.
This means that some SMs have CVs which run six or seven pages, and that's quite normal.