Bookmarks help you identify and jump to specific places within your script (see Jump to Bookmarks).
Bookmarks are displayed in the editor’s gutter, so you will not be able to see them unless the gutter is both visible and sufficiently wide. If line numbers are also displayed in the gutter, bookmarks may be harder to see. To control line number and gutter display, see Editor Options.
Note that bookmarks are not preserved when you close the editor.
To toggle bookmarks:
Place the cursor on a line in your script and, from the editor’s pop-up menu, choose Toggle Bookmark and a given bookmark number.
If the bookmark you selected was not displayed on any line, it is added to the line where you placed the cursor. If the bookmark you selected was displayed on the line where you placed the cursor, it is removed. If the bookmark you selected was displayed on a different line, it is moved to the line where you placed the cursor.