It should be a standard stereo 1/8" jack (it is on my 910H)... for a paddle, tip is dot, ring is dash, and shell is common. You have to set "paddle" from the SSB/CW "set" mode, and you can choose normal or reverse polarity, or "bug" mode.
73, George, KA3HSW
went to plug in my CW paddle to the back of my IC-910H,,, the manual shows a standard 1/4 inch phono plug,,, the back of my radio has something else... I havent turned it all the way around to see what it is, have to disconnect lots of wires,,,but it isn't a 1/4 inch plug... anyone else notice this? Bob DM33