Requested feature overview description.
Allow certain types of tags link each other so we can obtain more specific results when searching.
Why would it be useful?
Let's say that I'm looking for male blaziken pictures, but when I type "male Blaziken" in the search bar, it would be very likely to find a female Blaziken with a male partner. Since I want a male Blaziken without minding about the partner (solo, M blaz/F partner, M/M, etc) a possible solution would be, in example, tagging the picture as blaziken:male to specify that there is indeed a male Blaziken in the picture regardless of their partner.
What part(s) of the site page(s) are affected?
Tagging System, Posts System.

This would be a great feature and has been brought up many times, but is not currently feasible in our tag system. Maybe someday that will change.

What are you trying to specifically search for?

BlackLicorice said:
What are you trying to specifically search for?

FurryLover121 said:
I'm looking for male blaziken

Eggplant said:

Just trying to be helpful! I think I’ve misunderstood the question :V

Seems like another area where we wouldn't be able to have nice things because of intersex...Ideally you'd have a tag and a symbol like so Blaziken♂ Blaziken♀...something like that...then maybe this for ambiguous Blaziken?.

However when you have to factor in dickgirl/cuntboy/herm/maleherm and that would kinda mess up the whole symbol idea.

That's a limited solution to a specific problem. More broadly what OP is describing is what I have previously called character-specific tagging. Where a user might want to search for a character with certain tag combinations like male blaziken or embarrassed nude female.

Currently a search for clothed female tiger returns stuff like post #1272386 which is correctly tagged with all 3 but doesn't actually give you a clothed female tiger like post #30836. Or maybe you want a dickgirl fox. Character-specific tagging skips stuff like post #696716 which includes a fox and a dickgirl but it isn't what you're trying to search for. It's more precise but also way more work.

This still sounds completely unfeasible.
We can't even get the basic tags tagged, so who's going to tag all the tens of millions of combos?

It sounds good on the paper, but I can't see it working in practice.

Imagine tagging those for something such as this:
post #37160

^{ambiguous_gender:charizard wings:charizard angry:charizard breathing_fire:charizard ambiguous_gender:yoshi green_body:yoshi female:princess_peach human:princess_peach clothed:princess_peach pink_dress:princess_peach princess:princess_peach princess:princess_daisy... *five hours later* prince_of_all_cosmos:happy}

Genjar said:
This still sounds completely unfeasible.
We can't even get the basic tags tagged, so who's going to tag all the tens of millions of combos?

It sounds good on the paper, but I can't see it working in practice.

Imagine tagging those for something such as this:
post #37160

^{ambiguous_gender:charizard wings:charizard angry:charizard breathing_fire:charizard ambiguous_gender:yoshi green_body:yoshi female:princess_peach human:princess_peach clothed:princess_peach pink_dress:princess_peach princess:princess_peach princess:princess_daisy... *five hours later* prince_of_all_cosmos:happy}

My own solution to this would be far simpler: Object-oriented tagging.

Basically, it would be possible to define any number of objects and then place tags within those objects.

So for instance, this image:

https://e621.net/post/show/1602829/2018-3_toes-3-3-berry_ranieri-black_nose-blue_eyes

Would have both characters as objects.

Object 1:
-berry_ranieri
-otter
-female
-etc.

Object 2:
-cat
-female
-etc.

And the searching would allow for searching of tags that are attributed to the same object.

That said, it gets complicated when you try to specify what exactly should qualify as an object of sufficient importance. And it would result in a lot of redundancy of tags (in the example given, the female and pussy tags would be duplicated, at minimum).

Still better than trying to link specific tags together, and is a general system which can apply to many situations.

I think e6's tag system is good as it is.

BlackLicorice said:
I think e6's tag system is good as it is.

e6's tagging system is a good balance between searchability and simplicity and increasimg one undoubtably lowers the other.

-2 on OP's specific idea, link tags, because the premise obviously prompts a combinatoric explosion of tags.
So not just 'I don't like it' but 'it obviously couldn't work'.

Tag groups otoh might work, but I'd want to see a
reasonably solid and complete picture of how it would work. Nobody's done that yet AFAIK (and I include external work like RDF tuples in that statement. They're just machinery with no real UI sorted out.)

Until then I have to agree that they are unlikely to justify themselves, even if we figure out how to make them competitive with the performance of the current relatively simple system. (which we haven't yet done either)

What if this proposed search syntax is limited to gender-related tags only?

Then that would be

{m,f,herm,intersex,cuntboy,dickgirl,ambiguous} ->7 items, times ~1200 species tags (including only the ones with a tagging count >100). == 8400 'link tags'.

If you include all species tags that have >= 1 tagging, then there are about 9450 species tags. Times 7, is 66,150 'link tags'.

To be fair, that is only the ideal (perfectly tagged) state. But since search is effective only in proportion to the degree that tags are correct, it seems reasonable to assume either :

a) things will converge towards that state and the search will work, or

b) they will not converge and the search will be relatively useless.

Based on the current state of basic tagging[1], I'm far more inclined to believe b) .

[1] all posts should have all appropriate sex tags [m,f, etc]; they should have all appropriate sex-pairing tags [f/m,m/m,f/f, etc]; all applicable species tags; and the number of characters should be tagged [solo,solo_focus,duo,duo_focus, group, zero_pictured]. Perhaps commonly blacklisted tags (scat, cub, rape, vore, etc) should also be applied where appropriate.

FurryLover121 said:
What if this proposed search syntax is limited to gender-related tags only?

As I see it, it'd make little sense to implement such a major feature only to arbitrarily limit it to a small number of tags.