Great, Hank. I worked at a big mutual fund company that hired a new director of marketing and communications, probably a $300K job. She spelled the plural of prospectus (prospectuses) as prospectus' -- and for the sake of clarity, I will avoid ending the sentence properly punctuated right there ("prospectus.'") because of the folks who simply wouldn't understand it.
Wouldn't the plural of prospectus be "prospecti"? It is made from Latin roots, and that is the proper Latin treatment for words ending in "-us".