LF_ constants represent the "link flag" of an entry, or more commonly, the "entry type". This is the "old way" of indicating a normal file.

[Visual Basic]
Public Shared ReadOnly LF_OLDNORM As Byte
[C#]
public static readonly byte LF_OLDNORM;

See Also

TarHeader Class | TarHeader Members | ICSharpCode.SharpZipLib.Tar Namespace