A custom requirement type may be edited in the system's Settings menu, located in the left main vertical panel. Navigate to the Types secondary menu and then to the Requirement tab.
To edit a requirement type, click on the vertical three dot menu for the specific type and click Edit. Default system types will not have the vertical three dot menu as they are not editable. The type description and the associated projects may be edited. The name and prefix may be updated if the custom type has not been used in a project yet. If it has been used, the name and prefix fields will not be editable.