The .info file is the center of interaction between applications and
Workbench.  To help support the Workbench iconic interface and manage
.info files, the Amiga operating system provides the icon library. The
icon library allows you to create icons for data files and directories
under program control and examine icons to obtain their Tool Types and
other characteristics.

 icon library data structures 
 icon library functions 
 the tool types array 
 example of reading icons and parsing tool types