Not sure where you got the question marks from, but he's talking about ellipses (two or three periods in a row, like '...'). It's actually a stylistic choice and there's nothing inherently wrong with using it, but it is generally considered unprofessional and overuse is extremely annoying for readers.

I misunderstood what the GGP was referring to. As far as I know, ending a sentence with ellipses is considered improper English except for some special cases.