Missing information in MS-OXOAB document - Exchange Offline Address Books‏

Dear Sirs from Microsoft,
 
 
Im Reading the document MS-OXOAB that describes the structures of offline Address Books. The document is available in:
 
Online:  http://msdn.microsoft.com/en-us/library/ee218186%28v=exchg.80%29.aspx
Offline: http://download.microsoft.com/download/5/D/D/5DD33FDF-91F5-496D-9884-0A0B0EE698BB/%5BMS-OXOAB%5D.pdf
 
I have Exchange 2013 client, and noticed that it creates ANR and RDN índex files for the offline address book on the path:
Homedrive:\\Users\UserName\AppData\Local\Microsoft\Outlook\Offline Address Books\GUID
 
 
The udetails.OAB is consistent with de structure described in the document for version 4 OAB file structure, since the first 4 bytes of the header equals 0x00000020 as described in page 40. But inspecting the header of the ANR and RDN índex files, i noticed that the first 4 bytes of each file, that should identifiy a documented OAB ANR or RND version, are not documented in this doc, since the first 4 bytes of the ANR and RDN files there are stored with 0x00000022.
 
I suppose the 4 byte 0x00000022 would identify the version 4 for ANR, RDN and PDN índex files for version 4, since they are the only that are missing in the document.
 
The ANR, RDN and PDN for version 2 and 3 are present in the document, but version 4 not.
 
 
Can you please address this issue, or am i missing some document?
 
Thank you in advance.
 
Peter.