Exact definition of "tag poisoning"

If you've been in the booru space for more than 5 seconds you've probably heard the term "tag poisoning" tossed around, but I've never seen it exactly defined. I used to think it meant basically meant using a tag incorrectly (thus you are "poisoning" that tag's well by adding incorrect images to it). For instance if you tag "huge_ass" on an image where the ass either isn't huge OR the ass isn't visible at all.

However on another form I saw another user define it something more broad. The exact quote here:
"Poisoning is alterations to the environment that results in a reduction of the site's healthy tagging environment. Over complicated tags, unauthorized creation/removal, failure to adhere to Terms of Service, banned material or other types of vandalism can be considered as poisoning attempts."

...so is that true? Cause that's much broader than I initially thought. That's like...everything you can do wrong concerning tagging, basically.

Anyways I thought it would be cool to try and get an "official" definition and maybe even add that definition to the help:glossary page for future use.

i can't speak for other boorus, but the terms i see used here for this type of behavior are mistagging (intentionally or unintentionally misusing a tag), and vandalism (intentionally making bad-faith edits). mistagging can boil over into vandalism if it's severe enough or if pointed out and not addressed.

I have seen a tag on Pixiv called 検索妨害 that was similar to the above content.

Personally I think of it as well intentioned devaluing of a tag, slowly "poisoning" it. For instance tagging post #10318606 as "blue_hair" is poisoning blue_hair because while it's technically correct it's not what people are searching for. Another example might be something like adding "witch" or "fairy" to characters because they are canonically even if they visibly don't look like the stereotype the tag is for. post #5194987 being tagged fairy is a good example of what I'd consider poisoning.

zetsubousensei said:

Personally I think of it as well intentioned devaluing of a tag, slowly "poisoning" it. For instance tagging post #10318606 as "blue_hair" is poisoning blue_hair because while it's technically correct it's not what people are searching for. Another example might be something like adding "witch" or "fairy" to characters because they are canonically even if they visibly don't look like the stereotype the tag is for. post #5194987 being tagged fairy is a good example of what I'd consider poisoning.

There's a counter argument for that picture though, if I search Touhou and fairy I'd be looking for art that includes her even if she's not drawn with her wings (same for the other fairies)

Space_Force_Detective said:

There's a counter argument for that picture though, if I search Touhou and fairy I'd be looking for art that includes her even if she's not drawn with her wings (same for the other fairies)

No that's the exact mentality that leads people to poisoning the tag. You wouldn't tag vampire on every Flan or Remilia, just like you wouldn't tag Kagerou with werewolf but instead wolf girl.

Space_Force_Detective said:

There's a counter argument for that picture though, if I search Touhou and fairy I'd be looking for art that includes her even if she's not drawn with her wings (same for the other fairies)

For your reference:

Quoted from howto:tag

Tag what you see, not what you know. In other words, only tag the visual and factual elements in the image. For example, images where the full moon is prominently depicted will have a full_moon tag.This also applies to characters. For example Remilia Scarlet is a vampire, but don't tag every picture depicting her with the vampire tag. Only use the vampire tag if the characteristics are clearly visible.

zetsubousensei said:

For instance tagging post #10318606 as "blue_hair" is poisoning blue_hair because while it's technically correct it's not what people are searching for.

I agree, but it should be pointed out that it used to be our policy to tag streak colors with the main hair color tags.

Space_Force_Detective said:

There's a counter argument for that picture though, if I search Touhou and fairy I'd be looking for art that includes her even if she's not drawn with her wings (same for the other fairies)

One user agreed with this and added fairy to a large number of Sword Art Online fairy characters whether they appeared as such or not. Guess what happened.

Hmmm...yes...I think well-intentioned or ill-intentioned doesn't matter at the end of the day, if you're watering-down a tag with incorrect results then you're poisoning it.

Kinda hard to concoct a perfect definition for this though...maybe something like:
"The dilution of a tag's meaning by intentionally or unintentionally mistagging it, or tagging it when it's not present, leading to inaccurate search results when using said tag (thus "poisoning" those results)"

I recall when I did some halterneck backless crusade because I found such outfits the... most alluring, and so I severely tagged Ganyu, Yelan, miss Siren, Lupa and some more based on what I thought was factual. I learned that I had to tag based on what's both shown and true. Both, not just either. (Examples: Twilight Blossom outfit weren't really halterneck at all; Yelan's back is out of sight)

Thanks for the lesson.