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 : 93 solved out of 328
- graph theory : 35 solved out of 134
- ramsey theory : 23 solved out of 71
- geometry : 17 solved out of 57
- additive combinatorics : 15 solved out of 49
- unit fractions : 18 solved out of 48
- primes : 7 solved out of 32
- analysis : 12 solved out of 32
- arithmetic progressions : 8 solved out of 23
- distances : 4 solved out of 22
- additive basis : 5 solved out of 21
- combinatorics : 11 solved out of 19
- irrationality : 1 solved out of 19
- chromatic number : 5 solved out of 18
- sidon sets : 3 solved out of 18
- set theory : 4 solved out of 18
- covering systems : 5 solved out of 17
- cycles : 5 solved out of 16
- factorials : 1 solved out of 15
- turan number : 3 solved out of 13
- polynomials : 7 solved out of 13
- divisors : 6 solved out of 11
- binomial coefficients : 2 solved out of 10
- complete sequences : 2 solved out of 8
- probability : 3 solved out of 8
- iterated functions : 0 solved out of 7
- hypergraphs : 1 solved out of 5
- discrepancy : 3 solved out of 4
- powers : 0 solved out of 4
- convex : 3 solved out of 3
- group theory : 0 solved out of 3
- primitive sets : 1 solved out of 3
- squares : 1 solved out of 2
- diophantine approximation : 1 solved out of 2