Some company names and symbols are obviously logos, but what about things such as childrens clothing that has a knitted pattern on it such as the muppets for example, or toys that copy characters from TV programmes? Sorry if this has been covered before.
Characters from TV programmes are definitely copyrighted, for knitted patterns it depends on each case. Best way is to upload and see the result, cause hypothetical situations are hard to be discussed.
If there is a text in the photo, that is not in English or other well-known languages, admins generally tend to reject because they can't be sure if it's a brand name or just a simple word like "restaurant".
For logos and images; if you try to upload a child's t-shirt with Mickey Mouse on it, it is definitely a copyright, even if the very little part is visible. Generally, try to get rid of every logo, and suspicious text. Most of the time, they don't add anything to the photo.
I have serious problems with sneakers, they always have huge logos on every side of them and it's very hard to clone it out.