# Tag management 2021

New year, new tag management thread.

Rules of the game are basically the same:

• A particularly bad tag (a rule of thumb: “if I can't imagine a person classifying a tag as either interesting or ignored, I'm getting rid of it”),
• A tag that should be a synonym of an existing one,
• A tag that used for two or more completely unrelated things,
• A need to create a new tag.
• Wait a couple of days before implementing a suggestion.
• After the problem described in an answer is resolved, please edit it to say so.

Also, note that one may use [tag:calculus] for , i.e. tags on the main site, and [meta-tag:discussion] for , i.e. for tags on the meta site.

Note that, in some cases, it might be better to have a separate question. Typically this happens when a longer discussion is needed and several possible answers are expected, since answers to a question provide more space for a more detailed discussion than comments under an answer in this thread.

Resolved: The renaming and synonymizing has been done.

Proposal:

1. Rename the to .
2. Create the tag synonym $$\to$$ .
3. Create the tag synonym $$\to$$ .
4. Create the tag synonym $$\to$$ .

This is related to, but distinct from, J. W. Tanner's proposal, in that it does not create any new tags. The idea has been discussed in the tagging chatroom.

Unless there are any objections, I will implement this proposal in a week.

• I see that you've linked to chat - here is a link which shows the conversation that spans two days. (Although in the first day there are mainly examples of questions about dot product and your messages about updating the tag-info.) And, of course, if the discussion in chat continuous, we can add more to the same bookmark. – Martin Sleziak Jan 7 at 9:36

Resolved: Both tags renamed.

Proposal: Rename to , to

Nothing too crazy here, just some quick grammar fixes.

$$\textbf{Resolution}:\;$$ The tag dot-product was created by Xander Henderson;

$$\textbf{Proposal}:\;$$ Create the tag dot-product.

There is a tag for cross-product, but not one for dot-product.

There is a tag for inner-product-space, but that is more abstract than the usual dot product for $$\mathbb R^n$$.

• Seems like a synonym would be the ideal solution here, redirecting dot-product to inner-product-space But on the other hand this may confuse users who would be the target audience of dot-product – Alexander Gruber Jan 5 at 1:29
• Are there really enough (unique) good questions about the dot product to justify a tag for it? – Alexander Gruber Jan 5 at 1:30
• @AlexanderGruber I have added a few random examples in the tagging chatroom. Maybe somebody is able to find more of them - and looking at some of those question might help in deciding whether a separate tag for dot product would be suitable. – Martin Sleziak Jan 5 at 6:42
• @AlexanderGruber I agree that a dot-product -> inner-product-space synonym would be ideal. I have edited the inner product space tag wiki in anticipation of such a move (i.e. I have highlighted the dot product a bit more). The goal of the edits was to prevent confusion on the part of "dot product" users. – Xander Henderson Jan 5 at 13:21
• @FearfulSymmetry: I edited accordingly – J. W. Tanner Jan 12 at 18:26
• @MartinSleziak: thanks for the good examples – J. W. Tanner Jan 12 at 18:27

Proposal: create qr-decomposition

There are already lu-decomposition, cholesky-decomposition, schur-decompsition and other related tags on eigenvalues or the SVD. But not qr-decomposition, while there seem to be many questions on this.

Alternately, as suggested by Cameron Williams in this (now deleted) question, we might merge all those tags with the tag matrix-decomposition, which already exists. Not my preferred choice, but it's debatable.

Proposal: Add the meta tag deleted-comments.

This tag is present on meta.SE: https://meta.stackexchange.com/questions/tagged/deleted-comments.

The current meta tag includes

• deleted questions

As a result, to search for meta questions about deleted comments, one has to use the query string "deleted comments" under the tag . Such user experience can be improved by the creation of the meta tag deleted-comments.

How about a tag for L'Hopital's rule?

I have asked a few questions myself involving L Hopital's rule specifically, such as:

'Proof' that $f''(x)=\frac{f'(x)}{x}$

Does L'Hopital's rule imply that $\lim_{x\to a}\frac{f'(x)}{g'(x)} = \lim_{x\to a}\frac{f(x)}{g(x)}$ always?

It would have been useful to have a tag to show that L' hopital's rule was the crux of my questions.

I have also seen many questions that ask about how L Hopital's rule works in a specific case; again the main topic related to their questions is L' hopital's rule, and a L'Hopital's rule tag would have been useful to them. Search "l'hopital" on the search option and many such questions come up.

• Can you explain why you think that this tag is necessary? L'Hospital's rule is a tool for computing limits. Generally, someone here posts a question about a limit, and expects folk to find that limit for them. The tools used to do this are typically irrelevant. There are folk who want to do things without using certain tools, for which the limits-without-lhopital tag exists. I don't, however, see a compelling reason to include a "lohpital" tag. That said, my mind is open, and I'm willing to be convinced. – Xander Henderson Jan 8 at 0:06
• @XanderHenderson please see my edit. Unfortuantely I do not have any links of other's questions that include L Hopital's rule at the moment. – A-Level Student Jan 8 at 9:12
• So the clarification you have added now can be summarized as: The tag would be for questions about L'Hospital's rule - and not for computations of limits L'Hospital's rule. (Unless they are in some way specific to LH - for example, asking why LH works/does not work in some limit.) – Martin Sleziak Jan 8 at 9:13
• I have collected some possible examples of such questions here in chat. Maybe also some other users might have suggestions (or at least say whether this would be the kind of questions suitable for that tag). – Martin Sleziak Jan 8 at 9:54