The bulk update request #8143 is active.

remove alias art_collab (0) -> collaboration (11233)
remove alias art_collaboration (0) -> collaboration (11233)
remove alias multi-artist (0) -> collaboration (11233)
remove alias multi_artist (0) -> collaboration (11233)
remove alias multiple_artists (0) -> collaboration (11233)
remove implication multi-animator_project (4) -> collaboration (11233)

Reason: Taggers are confusing collaborative tag with collaboration tag.
I submit
1) that the tags are too similar, AND
2) artist collab tag should be artist_collaboration (or something similarly more specific then just collaboration).

Wiki of collaboration: "Images or animations that were created, or worked on, by two or more artists."

470 posts tagged with collaboration, but only have ONE artist tag: https://e621.net/posts?tags=collaboration+arttags%3A1
(75*6 +20 = 470)

example:
post #2805537
tagged with collaboration, but only one artist (shows collaborative_sex).

On 2019-09-18 tags art_collab (alias #34758), art_collaboration (alias #34757), multi-artist (alias #34756), multi_artist (alias #34755), and multiple_artists (alias #34754), were all aliased to collaboration with alias "Reason" fields blank,
and with NO associated forum link in "Forum Post" fields.
(I thought maybe there was no Reason field back then, but an earlier alias [ alias #34753 ] from hours earlier, did have something in its Reason field)

EDIT: The bulk update request #8143 (forum #405309) has been approved by @scaliespe.

BUR part 2 draft:

alias art_collab -> artist_collaboration
alias art_collaboration -> artist_collaboration
alias multi-artist -> artist_collaboration
alias multi_artist -> artist_collaboration
alias multiple_artists -> artist_collaboration
imply multi-animator_project -> artist_collaboration
category artist_collaboration -> meta

(since collaboration is in Meta category)

example #2 of tagger confusion: 209 posts* tagged with collaborative, and 2-or-more artist tags, BUT NOT tagged with collaboration:
collaborative arttags:>1 -collaboration -conditional_dnp -third-party_edit -sound_warning -bunniithundii

(75*2 +59 = 209)

* = probably includes some false positives including maybe some with 2(or-more) tags for SAME artist:
(is komiko aka komikoe?)
(all 4 bunniithundii posts also tagged with bynubunnii artist tag ... https://e621.net/users/1494149 which has username BynuBunnii which i assume is artist's e621 account)
(+ potentially other duplicate tags for same artist)

listerthesquirrel said:
example #2 of tagger confusion: 209 posts* tagged with collaborative, and 2-or-more artist tags, BUT NOT tagged with collaboration:
collaborative arttags:>1 -collaboration -conditional_dnp -third-party_edit -sound_warning -bunniithundii

(75*2 +59 = 209)

* = probably includes some false positives including maybe some with 2(or-more) tags for SAME artist:
(is komiko aka komikoe?)
(all 4 bunniithundii posts also tagged with bynubunnii artist tag ... https://e621.net/users/1494149 which has username BynuBunnii which i assume is artist's e621 account)
(+ potentially other duplicate tags for same artist)

Also includes one post of epilepsy_warning collaborative arttags:>1 -collaboration -conditional_dnp -third-party_edit -sound_warning -bunniithundii

Also should probably mass update collaboration to the new tag

The bulk update request #8143 (forum #405309) has been approved by @scaliespe.

The bulk update request #8484 is pending approval.

create alias art_collab (0) -> artist_collaboration (0)
create alias art_collaboration (0) -> artist_collaboration (0)
create alias multi-artist (0) -> artist_collaboration (0)
create alias multi_artist (0) -> artist_collaboration (0)
create alias multiple_artists (0) -> artist_collaboration (0)
create implication multi-animator_project (4) -> artist_collaboration (0)
change category artist_collaboration (0) -> meta
mass update collaboration -> artist_collaboration
create alias collaboration_artist (0) -> artist_collaboration (0)
create alias collab_art (0) -> artist_collaboration (0)
change category collaboration (11233) -> invalid

Reason: Add lines
mass update collaboration -> artist_collaboration alias collaboration_artist -> artist_collaboration category collaboration -> invalid
on top of Lister's draft.

The alias for collaboration_artist is so that artist_collaboration will show up in the autocomplete when typing just collaboration, similar to how pool_(swimming) is aliased so that swimming_pool shows up when searching for pool.

Invalidation of the tag is due to ambiguity (used for both collaborative and artist_collaboration)