PPC Rules

I have a fashion website and want to increase my spend on PPC so I’ve been doing a bit of research. I’ve noticed that when you type in the name "ASOS" which is th UKs biggest online retailer, Topshop comes up as sponsered link. I was under the impression that this was against the rules, but I’vw found lots of instances, such as people will use the name of competitors brands in there PPC advert saying type "BRAND X" for a 20% discount on our site, surely both these styles of PPC are against the rules.
I currently manufactur my own clothing and it is made in the same factory as topshop, so the style is similar, does this mean I can use topshop as a keyword, surely not?

See original post by projectsclothing