from what i remember, this is no word limit. you can make it as many pages as you want and it will all print out for the programs. also, when you print out your PS, it might print out differently for the program, depending on the printer they use. (ie, if your PS prints out as 1 page on your printer, the last line of your PS might fall on a 2nd page on their printer).
anyway, the goal should be to keep it under a page since programs have tons of them to read and won't want to read anything longer than a page. this was reiterated to me many times.
hope that helps. 🙂