This plugin was born in the 2014 Copenhagen Code Camp to allow administrators to put notes on every page. See trello card.
If there is a need to add relevant information for any page on Jenkins the page note plugin gives the ability to create a note for each Jenkins page. The capability to the notes and to read them is restricted to users on the security group called "Page Note". The group only is viable for "Matrix-based security" and "Project-based Matrix Authorization Strategy" authorization methods. When added the notes stack on top of each other and the author of the note is displayed next to it.