@MartinSleziak I removed that tag because for that particular question, gradient is not a good tag. (The post asks about "gradient blowup" which was [is? not sure now] too specific to be a tag in its own right, but it does not have anything to do with the general concept of the "gradient".) I think the concept of "gradient" is useful as a tag generally speaking, though you need to think about its scope: do you want it to be only about the calculus concept, or include the geometric versions...