I'm validating my web pages with W3C's validator, and it gives me the following error when I try to use GET variables in my hyperlinks:
& did not start a character reference. (& probably should have been escaped as &.)
I'm using the standard format:
... href='url.php?var1=val1&var2=val2' ...
It's throwing this error numerous times with links from my affiliate programs, as well. Should I just ignore this?
You should encode the ampersands as they have special meaning in HTML:
... href='url.php?var1=val1&var2=val2' ...
In general browsers cope pretty well with unencoded ampersands, but it's good practise to encode them.