[MSDN Library June 1998] Optional Interfaces for the Visual Designer (21.0374838194387%)

MSDN Library Visual Studio 6.0 > Tools and Technologies > ActiveX Designer Programmer's Reference > Chapter 3: Designing and Implementing an ActiveX Designer > Creating the Visual Designer

[MSDN Library June 1998] Optional Methods in Control Interfaces (20.8694727891156%)

MSDN Library Visual Studio 6.0 > Platform SDK > COM and ActiveX Object Services > COM > Appendixes > ActiveX Control and Control Container Guidelines > Controls

[MSDN Library June 1998] Optional Report Message Properties (20.847197574682%)

MSDN Library Visual Studio 6.0 > Platform SDK > Database and Messaging Services > Messaging API (MAPI) > Guide > MAPI Programming Basics > Messages > About Message Properties

[MSDN Library June 1998] Optional Components Unavailable When User Profiles Are Enabled (20.7100187745349%)

MSDN Library Visual Studio 6.0 > Knowledge Base > Windows 95.x Retail Product

[MSDN Library June 1998] Optional Features for Address Book Providers (19.8469387755102%)

MSDN Library Visual Studio 6.0 > Platform SDK > Database and Messaging Services > Messaging API (MAPI) > Guide > Developing an Address Book Provider