A named dimension style is a group of settings that determines the appearance of the dimension. Using named dimension styles, you can establish and enforce drafting standards for drawings.
All dimensions are created using the active dimension style. If you don't define or apply a style before creating dimensions, AutoCAD applies the default style, STANDARD. To set the active dimension style, use the ActiveDimStyle property.
To set up a parent dimension style, you begin by naming and saving a style. The new style is based on the current style and includes all subsequent changes to the layout of the dimension parts, the positioning of text, and the appearance of annotation. Annotation in this case means primary and alternate units, tolerances, and text.
For more information about dimension styles, see “Use Dimension Styles” in the User's Guide.