The Chooser and Your Driver(IM:XP)

Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /: Chapter 3 - Printer Drivers / User Interface and Chooser Support

The Chooser and Your Driver
You need to define resources for your printer driver to provide a Chooser interface, which allows the user to select your driver from among the printer drivers available
on the computer.
The Chooser uses the look ('look') resource to generate the pop-up menu list of "Connect via:" options that it displays when the user selects your driver. Listing 3-30 shows an example of a look resource for the ImageWriter II printer driver, which supports serial, PAP, and PrinterShare connections.
Listing 3-30 The look resource for the ImageWriter II printer driver
resource 'look' (-4096, sysHeap, purgeable)
{
   2,    /* use the second in the list as the default */
   {
   "AppleTalk",   -4096,   isAppleTalk,   "ImageWriter";
   "Serial",      -4095,   iconCells,     "Modem Port";
   "Servers",     -4094,   isAppleTalk+isPrinterShare,
                           "ImageWriterIIIS";
   };
};
The look resource accesses each communications resource that you specify for your driver to determine parameter values for the type of connection that the user selects.