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- Help cleanup tags! 19 answers
I don't yet have the required reputation nor the answer-votes, yet I'd like to suggest identifying the tags
isoperimetry & isoperimetric-problems with the (already synonymous) pair
calculus-of-variations & variational-calculus. All four tags seem perfectly equivalent. (Or maybe some discussion will show they are not?)
Likewise for combinatorial-designs and design-theory.