What exactly are "double standards" for...? That is, some seem racist/sexist, so surely they could cause offense...?
Don't really know of some...and if I did I'd probably prefer to not mention them.
Really recommend that if you don't know what "Double Standards" mean, you use Google/Yahoo/Ask - any search engine - to look it up:
(Here's one explanation):
a rule or principle which is unfairly applied in different ways to different people or groups.
(you kind of get clues from the examples given already - different rules for different people applied to them when they are in a similar situation):
Here's a double standard that exists in my part of the world and always causes a lot of controversy... why is it OK for a black guy to call another black guy a word beginning with the letter N when any other person of a different ethnicity would be reviled for calling a black guy that word?
This double standard also applies to other racial and ethnic slurs.