Task Pane
A Task Pane hosts contextual properties, comments, navigation, and assistant workflows beside the active editor.
Editor canvas
Usage
Parameters
States and variants
The host application owns whether the pane is mounted or placed in a Split Pane. Add data-responsive="overlay" when the Office behavior is desired: the pane shares workspace width above 900 pixels, overlays at the inline end below 900 pixels, and becomes workspace-wide below 520 pixels. Its host must establish a positioning context, normally with position: relative.
Accessibility
Use <aside> when the pane is complementary to the editor and give its heading a stable accessible name. Return focus to the control that opened the pane when it closes.