X-MS-Exchange-Organization-AuthMechanism: possible values

Hi,

I am looking for the possible values and their description for the header called

X-MS-Exchange-Organization-AuthMechanism:

This X-header specifies the authentication mechanism for the submission of the message. The value is a 2-digit hexadecimal number.

What does the different values means exactly 04, 10, 03 etc....??

Thanks