ExhibitThe viewport scales in the title block shown are field value as extracted from the...

The object property that you should use when using the Insert Field command to generate the viewport scale, if the default scale list is being used, is the "Standard scale".

The "Standard scale" property is used to specify the standard scale factor for the viewports. It represents a value in the format of 1:n, where n is the scale factor. For example, if you set the standard scale to 1:50, the viewport will display objects at a scale of 50 units per drawing unit.

To use this property in the Insert Field command, you can select "Object" in the "Field category" dropdown and "Standard scale" from the "Field names" dropdown. This will insert a field code that will automatically update the viewport scale based on the properties of the viewport.