There are many tags which are used in combination with the transformation tag to provide details about the nature of the transformation.
There are tags which clarify what trait of a character is being changed like species_transformation, gender_transformation, and size_transformation
There are tags which clarify both what a character is before they transform and what they transform into like all the tags on the transformation tables in the transformation wiki.
There are tags which clarify the details surrounding the transformation like consensual_transformation and lust_transformation
There are tags which clarify what a character is transformed into like goo_transformation, cock_transformation, robotization and furrification.
There are tags which clarify the cause of a transformation like transformation_through_sex, and goo_transformation
Though they are less common, there are tags which clarify what a character is before they transform like reverse_robotization.
While not always transformation, there are also tags which clarify a role or presentation that a character gains like feminization, bimbofication and dronification
And of course there are others that don't fit into any of these categories.
You may have noticed that goo_transformation is listed twice. This is where the problem begins. The majority of these tags are ambiguous about what they refer to. As an example,lust_transformation could just as easily refer to the cause of the transformation. Without checking, can you guess if suit_transformation refers to characters being transformed by suits, or being transformed into living suits? What about clothing_transformation? Does foot_transformation refer to a character's feet transforming, or a character transforming into a foot? What about breast_transformation? Both of these pairs have the same naming pattern, but refer to opposite effects. It's not just the blank_transformation tags that have this problem. objectification could refer to a character transforming into an object, but according to it's wiki, is only supposed to be used for characters in the role of an object. Despite that you'll find many posts in objectification that should only be in inanimate_transformation. In the worst cases like goo_transformation there is no attempt to create the separation between transformation into a goo creature and transformation caused by goo. These ambiguities have also lead to the creation of duplicate tags robotification. Due to the extra friction using these tags has, many of these tag are under applied, for example cowification has only 3 pages despite being an incredibly popular theme in transformation.
Because of this, I think it would be valuable for the wiki to recognize these categories of tags and to create a standard for how transformation tags should be named. Splitting the wiki into these categories should make finding the most popular tag for a specific scenario much easier, which should help taggers apply them correctly, and help searchers find tags they may not have used otherwise. Right now the wiki loosely follows some of these categories with the transformation tables and the "Transformation reasons" section. Creating a standard for tag names would be much more difficult, and would require many aliases and bulk updates. Deciding on a standard that can catch most edge cases is also hard. It's far from perfect, but the following could be a good starting point for discussion.
for tags that clarify a trait of a character that is being changed.
*_to_*for tags that clarify a character's both before and after a transformation. form_transformation tags already follow this pattern. gender_transformation tags abbreviate this pattern, so they would need to be changed.
transformation_*for tags that clarify details surrounding the transformation. This is far from perfect, and I much would prefer something better.
transformation_by_*for tags that clarify the cause of a transformation. I like this format because it cannot be confused with the other categories, and because there are already many tags using it.
Tags that clarify what a character is before they transform are already uncommon. I don't think they need a naming pattern at this time.
The biggest problem is tags that clarify what a character is transformed into and tags clarify a role or presentation that a character gains, since I cannot think of anything other than *ification and *ization for both, and those two formats are similar enough that I would expect them to cause confusion, in addition to causing a lot of awkward tag names for whichever category gets *ization
Thoughts and input are appreciated, I doubt I have the best solution to these problems.