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 : 109 solved out of 395
- graph theory : 58 solved out of 192
- ramsey theory : 30 solved out of 81
- geometry : 22 solved out of 80
- additive combinatorics : 26 solved out of 68
- unit fractions : 20 solved out of 48
- primes : 7 solved out of 39
- chromatic number : 10 solved out of 39
- distances : 6 solved out of 37
- combinatorics : 17 solved out of 36
- analysis : 12 solved out of 32
- arithmetic progressions : 8 solved out of 23
- sidon sets : 3 solved out of 22
- additive basis : 6 solved out of 21
- factorials : 2 solved out of 20
- turan number : 4 solved out of 20
- irrationality : 1 solved out of 19
- cycles : 4 solved out of 18
- set theory : 4 solved out of 18
- covering systems : 5 solved out of 17
- binomial coefficients : 2 solved out of 17
- divisors : 6 solved out of 16
- hypergraphs : 4 solved out of 13
- polynomials : 7 solved out of 12
- complete sequences : 2 solved out of 8
- probability : 3 solved out of 8
- iterated functions : 0 solved out of 7
- 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
- squares : 1 solved out of 3
- primitive sets : 1 solved out of 3
- diophantine approximation : 1 solved out of 2