[MSDN Library April 2000] Optional Report Message Properties (100%)
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 (29.4458653026428%)
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 Second Element (Only Used by X.25 SVC) (25.6145929694727%)
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 Implementation (24.1989707760499%)
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
[MSDN Library April 2000] Optional Printer Interface Driver Functions (23.9282541989664%)
MSDN Library - April 2000 > DDK Documentation > Windows NT 4.0 DDK > Graphics Drivers > Design Guide > Part 3: Print Components > Chapter 10 Supporting DDI Printing and User Interface Functions > Supporting Printer Interface Driver Functions