This is a database of riichi mahjong screenshots. There is no criteria, but try to keep the tags consistent (do a blank query on the search to get a full list of entries, and have a look at those tags -- a glossary is also linked on the upload page). Add the name of the player who formed the hand (Tenhou/whatever name and perhaps also IRC), since that is partly a function of this page. If you screw up or something message me on IRC and I will fix it. If it says an entry is already there, then it probably is.
Also, add Tenhou replay links if you like. They will just show up like any other tag, but if you have the link it would be helpful.