A few more words might help.  If you're asking how to get a photo of someone with tattoos accepted, you will need to submit a property release signed by the tattoo artist.  The artists holds copyright to their art, and needs to grant permission for its commercial use.  That is of course in addition to a model release.

No problem with tattoos in fotolia...

I avoid tattoos people.

How to delete tattoo?

I did a video shoot of a tattoo artist for Getty, I had to have a model and property release for the tattoo. They have sold well.

I've just got my first images rejected for showing tattos. I think the claim to have PR for tattoos is a bit ridiculous given the explosion of their popularity in recent years.

From my recent batch, getty accepted all the images showing tattoo.
Shutterstock rejected all of them where even a small part was visible (29 of them).

Can you imagine how bizarre the conversation would be? "Yeah, I'm the guy you tattooed 6 years ago. Can I have your permission to use my arm?".

I can understand when a work of art has a clear boundaries in space, such as the case with the Dancing Steps.
However, when the work of art becomes part of the person itself, don't you think we are sailing on somewhat different waters?

The canvas is the person himself and, in my opinion, the subject's consent should have the same value as the one signed by the tattoo artist.

I'm talking about fundamental issues of identity and property.
Don't you find the idea of someone gaining property rights on your body a bit outrageous?

It's funny to see that out of the big 4, only Shutterstock seems to be having this policy, all the others accepted the images.
I don't know if they've had issues in the past, but the scalded cat fears cold water, it seems.

iS always used to refuse unreleased tattoos. Surprised they've reversed that policy, but can't find any reference to tattoos on their lP wiki.

The educated and experienced photographers above obviously know how it works. However, that's just not how it should work, IMO.

For example, with a building that has strict protections on uses of it's design, you cannot take an isolated image and "sell it". But if it is part of a skyline among many buildings, it's inclusion should in no way be an issue. No one should be able to make a skyline unusable by adding their building to it, that would be ridiculous. Same with graffiti art. An isolated image of an artists work cannot be photographed and then resold via stock, that makes sense. But if an otherwise perfectly commercial image happens to include a spray-painted tag by some idiot, that should not render the entire image unsaleable. That gives an ridiculous amount of power to vandals (but that's the way Shutterstock handle's it, of course).

Same should go with tattoos. You cannot photograph a close-up of tattoo and then sell that image like your own without a release, that's not acceptable. But, if you have images such as chrisphoto has, it's ridiculous to require property releases for partially covered and nowhere near main subject tats.

And if in any of these cases, a buyer edits the picture down to just the copyrighted/owned/trademarked element, well that's among the things that the buyer should be ultimately responsible for.

Unfortunately, the real world vs how it "should" be are two different places.

Adobe (Fotolia) seems to be getting this right.
Quote from the requirement page - https://helpx.adobe.com/in/stock/contributor/legal/property-release.html

"Tattoos are considered works of art, so you need to take into consideration the prominence of a tattoo�s display and the content of the tattoo itself. You don�t need a release if the tattoo isn�t the main focus of the photo. However, a property release is required in these cases:

The tattoo is close up and the primary focus.
The tattoo depicts celebrities.
The tattoo�s subject is trademarked or copyrighted (e.g., a logo or character)."