User (driver) defined tags. 0x0700 - 0x0763 ∙ 1792 - 1891
IG_ISIS_TAG_USER_0 through IG_ISIS_TAG_USER_99 have special purposes which depend on each driver. For example, the SHOWDIB sample-only driver (a Windows 3.1 driver that can display an image in a window) uses IG_ISIS_TAG_USER0 to hold the window handle.
Driver-defined.
PIXFPACK.
Driver-defined.
A knowledge of the implementation of these tags is required in order to understand how to use them. Note that these are the only tags which are not automatically forwarded when set.
These tags are defined in header files but do not exist unless a custom driver creates them. They are provided as preset tag values that a driver can use to pass values without concern for conflicting with existing tag definitions.