This .NET class wraps the AcDb::TextVertMode ObjectARX class. 

It gives the vertical modes of the text. 

If vertical mode is set to any value other than .TextBase, then the text object's alignment point is used to determine the text's position. The position point is recalculated based on the text string and the alignment point's value. If vertical mode is .TextBase, then the position point is used to determine the text's position. The alignment point is recalculated based on the text string and the position point's value.

Public Enum TextVerticalMode
  TextBase
  TextBottom
  TextVerticalMid
  TextTop
End Enum

public enum TextVerticalMode {
  TextBase,
  TextBottom,
  TextVerticalMid,
  TextTop
}