Page banners are a new feature in Review Board 8. They give extensions a

consistent way of displaying important information at the top of any or

all pages, using little more than a TemplateHook and some context

variables, but allowing for more advanced interactions and content.
This guide covers how to create page banners, walking through basic

TemplateHook usage and working through subclasses for dynamic content,

custom templates for additional layout and scripting, and details like

how to use cookies and JavaScript to implement support for closing

banners.

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