Under Rules- What does “Does not contain” mean and can you give me an example?

Hello- I have been using the Rules to try to get rid of all the X rated emails that I continue to get even though I never go to any sites or open them I have over 100 rules and keep getting more. Now things are coming in looking like this... From sender-xuy then the subject looks like this s#L-**U^^ T  so, the word slut is under rules but when they put it like that I can not keep it out. Funny thing is I never got this kind until I started blocking all the easy x rated words. So I guess now I wondering what else I can do. What does "does not contain" Mean and how can I use it to block this kind of stuff out? Also Isn't there any way to know who the sender actually is so we can report them or block them completely? It is getting so out of hand and so disgusting to even open y emails. I realize you are all doing your best but there has to be a way to see that things that don't look right should just be kept from going to an email. Like a sender with just One letter. or all the other symbols that are put in the subject line.
Thanks