Use the Properties panel on Sectors to view and edit the properties of the selected sector frame.
To open the Sector dialog box, click on its border or within its header area (double-click in Explore mode, or right-click the sector frame and then choose Edit Properties from the menu that appears).
The properties panel lets you set documentation and styles for the sector frame, using the associated tabs.
To rename a sector frame, click on the name and edit that, just as you do for other building blocks.