Is it OK to use '&' in a directory name? For example: http:///www.widgets.com/products/blue-&-red/index.jsp Is that OK?
If it works then it's okay. Since it doesn't appear to work then it's not okay. IE gives an invalid syntax error. If you had bothered to do your own testing you would have known that. & is for index.jsp?blah=1&foo=2 Not for directories.
No, it's not. If you're going to do the & sign, make sure you put the proper HTML code in to make the & sign display: & Otherwise, search engine crawlers won't be able to recognize what it is, and some foreign users won't be able to see the symbol if you just type it on your keyboard.