You might have noticed that the tag inequation has been created recently. (See also a few comments and related links posted after the creation of the new tag in chat: https://chat.stackexchange.com/rooms/3740/conversation/the-inequation-tag.) The tag was created by the same user who posted the question Why isn't the term inequation widely used in English? on the Mathematics Educators site - so the discussion there might be a bit related to this.
- The tag creator pointed out that there are two separate Wikipedia articles inequation (current revision) and inequality (current revision). (Merging the two Wikipedia articles was discussed in the past, but it seems that for the purposes of Wikipedia the consensus was to keep the two articles separate.)
- The tag creator also suggested some basic tag-info for the newly created tag. (Although if there are supposed to be two tags, it should be made very clear in the tag-info what exactly is the distinction.1
- On the other hand, the tag inequality is one of the biggest tags on the site with almost 20k questions. So if some of the questions should be tagged with a new tag, it's quite likely to be a rather large retagging effort. So before going to be that, I think that it should be clarified: 1. Whether the new tag is actually needed. 2. What exactly is the distinction.
- Perhaps it's also worth mentioning that the tag inequation has been created (at least) twice in the past, in 2011 and in 2013. The SEDE queries used to find those posts can be seen here.
1Here is the wording suggestion by the tag creator. For the tag-excerpt: "For questions about solving an inequation or a system of inequations." (https://math.stackexchange.com/review/suggested-edits/1195346 https://math.stackexchange.com/posts/3212655/revisions) For the tag-wiki: "An inequality is a question, in the form of an inequality between two algebraic quantities. This inequality contains unknowns. To solve an inequality is to find the values of these unknowns that make inequality true. For example $3x-2>0$ and $(x^2-5x+6)(x^3-1)\leq 0$ are inequations to be solved." (https://math.stackexchange.com/review/suggested-edits/1195345)
I was a bit hesitant whether to post a separate question or whether to make a post about the new tag in the tag management thread. I decided to go for a separate question, since clarifying what the new tag is supposed to be for will probably need more place than comments under an answer in the tag management thread would allow for.