Defining Version Compatibility for Your Printer Driver(IM:XP)

Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /: Chapter 3 - Printer Drivers / Using Resources in Drivers

Defining Version Compatibility for Your Printer Driver
Your printer driver must contain at least one version ('vers') resource that defines its compatibility with QuickDraw GX. Version resources are used to record version information for Macintosh applications. You need to include a version resource with an ID of gxPrintingDriverBaseID that defines with which version of QuickDraw GX your driver is compatible. For the current version, the value of the first byte of the resource definition must be either 1 or 0. Listing 3-19 shows the version resource that defines QuickDraw GX compatibility for the ImageWriter II printer driver.
Listing 3-19 The QuickDraw GX version resource for the ImageWriter II printer driver
resource 'vers' (gxPrintingDriverBaseID, sysHeap, purgeable)
{
   0x01, 0x00, release, 0x00,
   verUS,
   "1.00",
   "1.00, Copyright \251 Apple Computer, Inc. 1989-1993"};
You can also include standard version resources in the resource files for your printer driver. These resources are described in Inside Macintosh: Macintosh Toolbox Essentials.