The list of saved Custom Naming Schemes for publishing is placed in Plug-ins\Common\Data\PublishItemNames.xml in user folder. The Custom Naming Schemes are formulas and it is not recommended to edit them. You could just delete them.
Hello, In Vectorworks 2018 the predefined list is stored in your user folder. You may remove custom name from the predefined list when you delete Plug-ins\Common\Data\PubliemNames.xml file. You could add Vectorworks enhancements for your requests. Thanks, Diana