There is a program that most platforms use that’s called the VeRO program. VeRo stands for Verified Rights Owner Program.
There are certain companies that don’t want you to sell their items, or use their trademarked names, logos, or phrases, without their permission. If a company finds that you have, they will contact the platform, who will remove the listing, and send you an email telling you why.
Your next step is to either contact the company to see if you can gain permission to sell the product, or forget about selling it. NEVER relist an item that a platform has removed for this reason without express permission from the company that you may do so! Any of the platforms will want to see written proof that you now are able to sell the item.
Another example of infringement is when you use an image or text that has been copyrighted. Always take your own photos, and use your own words in describing what you’re selling.
It is illegal to sell counterfeits, fakes, or replicas of brand-name items. Even if you claim it to be a fake, it is not allowed. This commonly happens with purses. For example, there are a lot of purses that say their “Coach”, but some are fakes. It is your responsibility to research this and only list when you are assured it is genuine.
There are a couple of words that I know of that can never be used when reselling. One is onesie, like the Gerber onesies for babies. That word is copyrighted and cannot be used. I instead use one piece instead of onesie.
Another one is Velcro. Even if you’re just describing the way a flap closes on a purse, you can’t use that word. Resellers use the phrase “hook and loop” instead of Velcro.
Not only can you eventually lose your ability to sell on these platforms if you repeatedly violate these rules, many companies will sue you for infringing upon their copyrights. It’s just really not worth it.