[MSDN Library April 2000] Optional Second Element (Only Used by X.25 SVC) (100%)

MSDN Library - April 2000 > Platform SDK > Networking and Directory Services > Microsoft SNA Server > SNA Device Interface Specification > Reference > Message Formats > Open(LINK)

[MSDN Library April 2000] Optional Fields (36.9076210127524%)

MSDN Library - April 2000 > Platform SDK > Web Services > Internet Information Services SDK > Programmer's Guide > Reference > Internet Database Connector Reference > Internet Database Connector Fields

[MSDN Library April 2000] Optional Report Message Properties (25.6145929694727%)

MSDN Library - April 2000 > Platform SDK > Messaging and Collaboration Services > Messaging API (MAPI) > Guide > MAPI Programming Basics > Messages > About Message Properties

[MSDN Library April 2000] Optional Features of ACM Drivers (19.8862024500322%)

MSDN Library - April 2000 > DDK Documentation > Windows 95 DDK > Windows 95 Documentation > Design Guide > Multimedia Device Drivers > Audio Compression Manager Drivers

[MSDN Library April 2000] Optional Implementation (18.4991576315861%)

MSDN Library - April 2000 > Platform SDK > Networking and Directory Services > Active Directory, ADSI, and Directory Services > Active Directory Service Interfaces (ADSI) > Implementing ADSI Providers > Provider Minimum Requirements