I was discussing this in the e621 discord server and was advised to make a thread, I'm basically proposing a policy change, or at least for the current policy to be more strict and easy to understand for image uploader and approvals.
The topic is whether an image where characters are in "costume," i.e. fursuit, plushsuit, animal costume, latex furry costumes, etc. should be considered "furry," and hence acceptable on e621, if there is no evidence that a human is wearing the outfit.
Some examples include:
post #2595981 post #1460809 post #1465633 post #1457790 post #3213446 post #2427009 post #2595807 post #2518872
These images have no way to tell whether there is a human or furry inside, at least not from what I can tell. A few them of them visible eyes underneath the costumes, but without a sense of skintone its not really possible to tell the difference between human or furry. A few of these have external confirmation that the person inside is a furry, such as the picture by panapoliz, an artist who frequently draws their cat fursona in animal costumes. For some of them, its even arguable if there is anyone in a costume, or if it some sort of animate inanimate/living clothing.
Now, in my opinion, these are furry images. There is no evidence that specifically a human is inside of these suits, and so these image present to me (as I'm assuming they do to most others) as "0% human, 100% a furry character (or at the least, 'furryish enough for my browsing')", and hence would fit in well on e621. The issue is that the current rule seems to be that these images are not furry since there is no evidence that a furry character is "in the image," and hence it is assumed that the costume wearer is a human instead of the other way around.
Unfortunately because it is often so hard to tell if a costume's occupant is a furry or not, it means this is often a coin flip on whether an image like this will be accepted or not. The images linked above were approved, but many others are not (I'm taking this from my own experience as an uploader).
To clarify, the following images would NOT be considered furry, and would not be approved for upload no matter the change in policy
post #538360 post #108670 post #3200897
These are obviously humans in costumes, and aren't allowed. (I understand some of these are grandfathered in, but I just mean that images "like these" would not be approvable, even if the guidelines were to change to allow the first set of images above to be consistently allowed).
The current ruleset seems to make it so images like those in the first set are approved and denied seemingly at random, at least in my own experience. I don't blame approvers for this, I think it is more that the current rules make it very difficult to identity what is and isn't "furry" due to loose definition in this case. In my opinion, not allowing the images in the first set due to them being "not furry" is going to keep this gray area no matter what, especially when considering that characters such as clothing-based animate_inanimates or those with a painted-on face are indistinguishable from people in costumes when you cannot see what is inside of them. It makes much more sense to me to consider cases like this "furry until proven otherwise," especially when characters like vanny (fnaf) are popular within the fandom but uploads of them need to be scrutinized so heavily to see if the artist drew a costume without any noticeably human elements (not allowed) or an anthropomorphic version of the design (allowed), especially when the average viewer likely won't notice the difference when browsing the tag.
Please feel free to reply with your opinions on this, it'd be nice to have a discussion over it and hopefully avoid future headaches I've had when deciding if an image is "furry enough" for e621 when I'm personally a fan of images of anthro animals in costumes, suits, and the like.