The bulk update request #2533 is pending approval.
remove implication micro_on_macro (23) -> micro (22499)
remove implication micro_on_macro (23) -> macro (35735)
remove implication micro_on_macro (23) -> size_difference (342889)
create alias micro_on_macro (23) -> extreme_size_difference (15830) # duplicate of has blocking transitive relationships, cannot be applied through BUR
mass update micro_on_macro -> extreme_size_difference
create implication extreme_size_difference (15830) -> size_difference (342889)
Reason: As I have talked about earlier here: https://e621.net/forum_topics/33545
The problem (exert from link above)
The problem with the current tagging practices for macro and micro is that it leads to a lot of micro content technically being macro content, and vice versa.
It is like tagging small_penis in an image between two obviously hyper characters just because one of the characters is 40% bigger than the other, people searching for small_penis is obviously not searching for an image with only hyper penises in it. (and tagging small_penis on that image is considered tagging abuse if one does it often enough.)
Likewise a person searching for macro isn't after an image of a normal sized character hugging a tiny character in an environment with clear indications that there is no abnormally large characters in sight. And vice versa for someone searching for micro, they don't look for a macro looming over a building while getting loomed over by a bigger macro themselves. (or a macro looming over normal sized individuals)
The micro/macro tag is also a bit ineptly named and should likely just be Excessive_size_difference
In short, the micro tag should like only be used if the character is smaller than normal. While macro should only be tagged for characters that are larger than normal. And if there is no indicators to what is normal sized, then excessive_size_difference is still a sufficient tag to describe the content. There is technically no need to tag such an image with macro nor micro.
We have some "minor" issues with tons of images being incorrectly tagged as micro and macro even if these tags aren't applicable to the image. And the micro_on_macro tag seems to be a culprit since it auto implies both micro and macro.
From the micro_on_macro wiki: (problem is in bold)
It is worth noting that, size being a relative concept, it is not strictly necessary for the smaller character to technically fall under the purview of micro, nor vice versa. The same effect can be achieved by juxtaposing an abnormally-sized character with a normally-sized one.
Since the micro_on_macro definition literally currently says that "there don't have to be a macro nor micro character in the image." Then it obviously shouldn't auto imply that there is a micro and macro character in the image.
Since the macro tag states:
Short for "macrophilia", a fetish based around the character(s) being gigantic in size.
While the micro tag states:
A character who is much smaller compared to average human size, typically less than a foot (30 cm) tall and often smaller.
Also, the micro wiki page should be updated to remove the whole:
...] Often accompanied by macro (if so, also tag size_difference). Note that neither character has to really be macro to e.g. get the micro_on_macro tag (and hence micro) since it is often impossible to determine which character, if any, is human-sized and which is larger/smaller.
Since this is literally talking about the micro_on_macro tag, and not about how and when to use the micro tag...
Macro and micro requires some context for the tags to be applicable in an image. Without context the image is just of a character of unknown size and therefore doesn't fit any of the two tags.
The micro_on_macro tag is about the more extreme sides of size difference, similar to how giga is an extreme of macro, and nano is of micro.
Therefore I think it is apt to rename micro_on_macro to what it actually is, ie extreme_size_difference. (and this surprisingly is a tag who's wiki effectively says "don't use this".....)