This .NET class wraps the AcDb::OsnapMode ObjectARX enum. 

It describes the way objects can snap.

Public Enum ObjectSnapModes
  ModeCenter = 3
  ModeEnd = 1
  ModeIns = 7
  ModeMid = 2
  ModeNear = 10
  ModeNode = 4
  ModePerpendicular = 8
  ModeQuad = 5
  ModeTangent = 9
End Enum

public enum ObjectSnapModes {
  ModeCenter = 3,
  ModeEnd = 1,
  ModeIns = 7,
  ModeMid = 2,
  ModeNear = 10,
  ModeNode = 4,
  ModePerpendicular = 8,
  ModeQuad = 5,
  ModeTangent = 9
}