The 'Add' button is used to parse a selected file or directory via the file selector window, in the browser database. The 'Del' button is used to delete the selected file from the browser database. One file or all files can be deleted. The 'Decl-Impl' button is a toggle button to see Declaration or Implementation of selected methods. The 'Close' button unmaps the browser control window and the visit window.
Some additional information appear in class and method windows.