As I posted in the retagging question, I want to improve the state of the differential tag and the suggestion seems to be positively received. Is this a good place to discuss what exactly should be done and how to go about it?

new-tag A new tag redundancy was created.

I'd hope that somebody more familiar with the differential tag than me might chime in.

Would it perhaps be reasonable to blacklist the tag differential - that would at least mean that it cannot be added to the older questions? And after it is blacklisted, perhaps the existing mess can be slowly dealt with.

@XanderHenderson Since the suggestion is to blacklist a tag, maybe it would be useful to hear from the mods. Since I see that you're around, I tried to ping you - at least to check what you thik about this.

@ronno To some extent, this is a very suitable room to discuss such thing. (In the sense that this room is intended as a place to discuss tag-related issues.)

At the same time, the question is whether you'll get some response. As you can see, this room isn't very active. At the moment, I only see five pingable users.

I have to admit that I am not too familiar with the tag differential.

@ronno Differentials are objects which come into their own in the study of smooth manifolds. I don't think that the existing tag wiki is all that great, but there is something distinct about differentials (vs derivatives).

Though it does seem to get misused.

@XanderHenderson Yes, there is a thing called differentials, there are actually some questions with that tag that are actually about differentials and line elements, and I note that in the answer to the meta question. But most (about 90% by my crude sampling) of the questions are not about that. Maybe we could move the 10% to infinitesimals?

On the other hand I realize that we should avoid bumping as large a fraction of the 1500 questions as possible

there seems to be 3 classes of questions with differential: (1) ones about infinitesimal constructions, (2) ones where the word differential can be replaced by one of "derivative" and "differential form", (3) ones where the tag differential was meant to be differential-geometry or ordinary-differential-equations or some such thing

My current suggestion is that the (1) usage should be renamed to something else, or if we can't come up with something better then merged with infinitesimals. (2) is probably fine to be synonymized to derivatives and (3) should be retagged.

If this is what we decide to do then we don't need to block or burninate the tag, and the influx of new questions seems to be <1 a day, so probably don't need to worry too much about that either