Deleting Unassigned Symbols
To delete an unassigned (unused) symbol
In the Resource Symbols dialog box, select the symbol that you want to delete, and click Delete.
Before deleting an unused symbol in a resource file, make sure it is not used elsewhere in the program or by resource files included at compile time.
For information on adding resources to managed projects, please see Resources in Applications in the .NET Framework Developer's Guide. For information on manually adding resource files to managed projects, accessing resources, displaying static resources, and assigning resources strings to properties, see Walkthrough: Localizing Windows Forms and Walkthrough: Using Resources for Localization with ASP.NET.