Each project maintains a list of recently accessed files that is sorted alphabetically but stored internally in a most recently accessed fashion. Whenever you open a file that file will be added to the current project's recent files list (the file is not added to all open project's recent file list, only the current one). To reopen a file from the Recent Files list, first make the list visible by clicking on the Recent Files tab or by selecting View | Recent Files. Identify the file you wish to reopen and double-click on that file item to open the file. To find out the full path name of a file item in the Recent Files list, hover the mouse over that item for a few seconds in order to reveal a tooltip that will display the file's full path name.
The size of a project's Recent Files list is configurable in Tools | Options under the General option category.
To manually remove an item from the Recent Files list, select the item and press the delete key. To remove all items from the Recent Files list, right-click the list and select Clear List from the popup menu that will appear.