By default, all label style types have a Standard label style.
When you create a new drawing without a reference to a template (.dwt), the label style types in the Label Styles collections in the Settings tree contain a Standard label style based on default settings. You can use the Standard style as-is, or you can use it as a basis for a new style by changing its properties and renaming it.
You can delete a Standard label style only when it is not referenced in a drawing or if it is not a “parent” label style with a subordinate “child” label style. For more information, see Defining Children of Existing Label Styles.