Permitted Addon Keymaps

Is there a list somewhere of permitted addon keymap names?

I’m trying to get my feet wet with Blender addon development, specifically with the VSE. I’m a little confused, though, about adding keymaps.

When I do (in register()):

wm = bpy.context.window_manager
km ='Frames')

and add keymaps to km, my keymaps work and they show up in the Input tab of User Preferences. This also works if I do

km ='Object Mode')

except in only works in the 3D view in Object Mode. But if I try

km ='Sequencer')

the shortcut does not appear in User Preferences and the keymaps don’t fire.

What is going on here? I checked the docs and the api, but I didn’t see any limitations on what addon keymaps can be named. I know the keymaps are getting created since I checked in the console.

Is there some list somewhere of permitted keymap names, or am I doing something else wrong?