Trademark

I was just reading a this post on the Boing Boing site, and it had a sentence that I found interesting for the Levi Strauss trademark drama.

"Trademark does not protect owners from others profiting on their marks --
trademark's purpose is to prevent vendors from misleading the public about the
origin of goods and services. If you use someone else's trademark ... you're totally in the clear, provided that the purchaser doesn't get confused about whose product he's buying."

IANAL but from that, it sounds like many of our favourite jeans could have arcuates and tabs?