The guild permissions system lacks an option allowing players to set their own public note, but not others. If this addon is installed by officers (or any rank with "edit public note" permissons), this solves the issue by giving guild members a way of setting their own note.
No configuration is required. The addon is completely light-weight, you won't even notice it is running as all note change requests are automatically suppressed from the chat window.
Any player whispering you "!note your note text" will have his own guild note set to the text he whispered.