Here is a list of all the current tags in the system, ordered by the number of problems with that tag. This is a work in progress - if you have suggestions of new tags to be added, or that certain tags should be added or removed from a problem, please let me know.

- number theory : 117 solved out of 419
- graph theory : 75 solved out of 208
- ramsey theory : 33 solved out of 86
- geometry : 25 solved out of 84
- additive combinatorics : 28 solved out of 73
- unit fractions : 20 solved out of 48
- primes : 7 solved out of 43
- chromatic number : 20 solved out of 43
- combinatorics : 20 solved out of 37
- distances : 7 solved out of 37
- analysis : 16 solved out of 33
- arithmetic progressions : 8 solved out of 23
- sidon sets : 4 solved out of 23
- additive basis : 6 solved out of 21
- factorials : 3 solved out of 20
- turan number : 5 solved out of 20
- irrationality : 1 solved out of 19
- hypergraphs : 6 solved out of 19
- divisors : 8 solved out of 18
- cycles : 6 solved out of 18
- set theory : 4 solved out of 18
- binomial coefficients : 2 solved out of 18
- covering systems : 5 solved out of 17
- polynomials : 8 solved out of 13
- complete sequences : 2 solved out of 8
- probability : 4 solved out of 8
- discrepancy : 3 solved out of 7
- iterated functions : 0 solved out of 7
- powers : 0 solved out of 4
- convex : 3 solved out of 3
- group theory : 0 solved out of 3
- squares : 1 solved out of 3
- primitive sets : 1 solved out of 3
- diophantine approximation : 1 solved out of 2