From AikiWiki - AikiWeb Aikido Information
[edit] Dogi/Keiko Gi/Gi: 道着、稽古着、着
Training costume. Either judo-style or karate-style GI are acceptable in most DOJO, but they must be white and cotton. (No black satin GI with embroidered dragons. Please.) The proper term is "dogi" or "keiko gi." "Gi" is often used in English, but would not be a proper term in Japanese.