With the code change in commit [19a1897]: "Fix changing toolbar icon set not change to matched panel icon set issue (Synchronize dockable panel tab icons with toolbar icons.)", the internal dock panels of Notepad++ are changing in sync with toolbar icons.

In concert with this change, plugins will need to be able to change their dock panel icons to be in sync with toolbar icons. To facilitate this need, please add a new plugin notification. Suggested name for this new notification: NPPN_TOOLBARICONSETCHANGED