 Apostrophes used in a non-standard manner to form noun plurals are known as "greengrocers' apostrophes" or "grocers' apostrophes", often written as "greengrocer's apostrophes" or "grocer's apostrophes".They are sometimes humorously called "greengrocers apostrophe's", "rogue apostrophes", or "idiot's apostrophes" (a literal translation of the German word "Deppenapostroph", which criticises the misapplication of apostrophes in Denglisch).The practice, once common and acceptable (see Historical development), comes from the identical sound of the plural and possessive forms of most English nouns.