What about creating [tag:small-uncountable-cardinals] tag? (The tag name is within the recently increased 35 character limits.) Looking at the main site, it seems that small uncountable cardinals (such as $\mathfrak p$, $\mathfrak t$, $\mathfrak b$, $\mathfrak d$, etc.) get quite a lot of attention on this site. For example, if you search for either of the cardinals mentioned before in the set theory tag, you can find a bunch of questions: [p](https://mathoverflow.net/search?q="mathfrak+p"+%5Bset-theory%5D), [t](https://mathoverflow.net/search?q="mathfrak+p"+%5Bset-theory%5D), [b](https://mathoverflow.net/search?q="mathfrak+p"+%5Bset-theory%5D), [d](https://mathoverflow.net/search?q="mathfrak+p"+%5Bset-theory%5D).) I think that creating a separate tag for this topic might made searching for such questions easier. Additionally people who are interested in the topic could follow the tag. (I.e., they could get those questions highlighted, they have easier access to recent questions [in their favorite tags](https://mathoverflow.net/search?tab=active&q=intags:mine), etc.) <hr> It seems that in the past mostly the tag [tag:set-theory] was used for questions about this topic. (Perhaps [sometimes](https://mathoverflow.net/search?q=mathfrak+%5Bset-theory%5D+%5Binfinite-combinatorics%5D) also [tag:infinite-combinatorics] tag, which is a bit more specific.) If the consensus is that the tag [tag:small-uncountable-cardinals] would be too specific and it is better not to create such tag, I would be grateful also for comments suggesting which tags can be used for questions where small uncountable cardinals are the main topic. In the past I have sometimes added [tag:infinite-combinatorics] to such questions - was it a reasonable choice?