i thought about it, and don't think so.

it is possible to have two different addons storing preferences under the same branch name. this notification ID is used to associate a button with some code in this particular addon that knows what to do about it being pressed.

in a similar vein, you were right (and i was wrong) about [ADDON_LOG_LEVEL_PREF](https://github.com/mozilla/addon-sdk/pull/1156#discussion_r5695263), as it pertains to a particular addon.