Sharepoint contant class

using System;

namespace Microsoft.SharePoint
{
 public enum SPFileSystemObjectType
 {
  Invalid = -1,
  File = 0,
  Folder = 1,
  Web = 2,
 }
}

using System;

namespace Microsoft.SharePoint
{
 public enum SPFileSystemObjectType
 {
  Invalid = -1,
  File = 0,
  Folder = 1,
  Web = 2,
 }
}

Microsoft.SharePoint.SPBuiltInFieldId