Keyboard shortcut convention for properties panel

We're designing for a B2B web based application (not mobile) where we have a panel on the right side of the screen showing details about a selection made in the main content area.

The panel can be opened and closed by clicking a button. We are considering adding a keyboard shortcut to also open and close the panel. What would be an appropriate shortcut key to use? Are there conventions we can follow? Our users use Windows.

Confluence have a similar design to us for the navigation where they use '[' as the shortcut.