The bulk update request #9105 is active.

create alias size_diff (0) -> size_difference (342246)
create alias size-diff (0) -> size_difference (342246)
create alias extreme_size_diff (0) -> extreme_size_difference (15785)
create alias age_diff (0) -> age_difference (67034)

Reason: Adds four aliases for the diff shortening of difference. Three of these have a history of being mistagged on posts:
https://e621.net/post_versions?commit=Search&search%5Btags_added%5D=size_diff
https://e621.net/post_versions?commit=Search&search%5Btags_added%5D=size-diff
https://e621.net/post_versions?commit=Search&search%5Btags_added%5D=age_diff

extreme_size_diff is included since it would be awkward to only have a diff variant for the base tag.

Other difference tag variants were not included since there was no history of mistagging these, though a separate BUR could be filed at a later date to address them either reactively or proactively.

EDIT: The bulk update request #9105 (forum #416895) has been approved by @spe.

The bulk update request #9105 (forum #416895) has been approved by @spe.