In Japan, we use four-letter tags like: EB43, FJ12, IKDD. The first two letters are abbreviation of location like EB=Ebina, FJ=Fujisawa, IK=Ikoma, and the rest of two indicate modules.
You can find these in the Japanese repeater list http://www.d-star.jp/D-STARjapan.pdf. 73, -- JI1BQW - Kay Ishikawa
