4.2.8 Supporting Older EFI Specifications and UEFI Specifications

Complying with different versions of the EFI Specification and UEFI Specification may be critical for some UEFI Driver implementations. If the driver is required to work on platforms that are conformant with the older EFI Specifications or UEFI Specifications and also on current and next-generation UEFI systems, then the UEFI Driver design must consider the requirements from multiple EFI/UEFI Specifications.
In many cases, the UEFI Driver can produce extra protocols to increase compatibility. In other cases, the UEFI Driver may be required to detect the UEFI capabilities provided by the platform firmware and adjust the protocols that the UEFI Driver consumes and produces.