I'm going to allow users to set an image with a link on my site. e.g. a profile picture and a profile link.

I will not let them upload said image, but let them give an url that i will insert into a img src.

I want to do basic checks for the best know xss patterns someone may use my site for, but thing is, i have no list of samples to check my functions works. As it is, even if I write a full RFC compliant parser to check every aspect of the URL, i will still not know what i should guard against.