- <STRONG>o</STRONG> Shading is used to identify <EM>X/Open</EM> <EM>Enhanced</EM> <EM>Curses</EM> material,
- relating to interfaces included to provide enhanced capabilities
- for applications originally written to be compiled on systems
- based on the UNIX operating system. Therefore, the features
- described may not be present on systems that conform to <STRONG>XPG4</STRONG> <STRONG>or</STRONG>
- <STRONG>to</STRONG> <STRONG>earlier</STRONG> <STRONG>XPG</STRONG> <STRONG>releases</STRONG>. The relevant reference pages may pro-
- vide additional or more specific portability warnings about use
- of the material.