The flexible editing environment gives you control of all aspects of this critical feature.
The column between the Document window and the Resources window contains the Editor toolbar.
These toolbuttons give you quick access to commands for:
To set a bookmark at the insertion point, select Edit > Toggle Bookmark. The bookmark symbol appears in the gutter. Bookmarks are not saved when you close the file.
Open Options > Settings > Editor to configure the editor display options.
Expand the Editor node to view and set options for these features: