Currently the book node outline form (/node/{nid}/outline) displays only the node title as the page title. This is confusing and inconsistent with the functionally similar node edit form (/node/{nid}/edit).
For example, for a book page titled "Introduction", the title displayed on the edit form is:
Edit Book page Introduction
While the title on the outline form is simply:
Introduction
Proposed resolution
Provide contextual cue in the title, eg:
Edit Book page outline Introduction