User-Defined Sheet Scale
When selected, sets the sheet scale when you select a value from the Scale list or type a value in the Scale Value box.
Changing a sheet scale manually does not change the drawing view scale of an existing drawing view.
Drawing View Scale
When selected, lets you choose an existing drawing view to apply its scale to the sheet. Eligible view types are principal (pictorial and orthographic), auxiliary, section, detail, broken-out section, broken, 2D model, 2D detail, and Quicksheet template views.
You can select a drawing view and then look at the values shown on the command bar to see its scale. In this manner, you can match the sheet scale to a specific drawing view.
Scale
Selects a scale value to apply to the working drawing sheet. This does not affect other sheets in the document.
Scale Value
Defines the working drawing sheet scale based on a value you type.
If the Scale Value results in a scale that is not currently available, it is added to the Scale list in the form of 1:X or X:1 where X is determined numerically by the Scale Value.
Example:
If you enter 5, then the sheet Scale list is set to 5:1. If you enter 1/3, then the sheet Scale list is set to 1:3.
Reset
Resets the scale to a previous value or to another drawing view you select.
You can use Reset to remove associativity with a drawing view by selecting the drawing view and then selecting this button.
Accept
Applies the current scale to the sheet. You also can right-click or press Enter.
Applying a sheet scale does not affect existing drawing views.