This document is incomplete

The following header entries have become obsolete since Keyman 5.0:

bitmaps	Obsolete (was reference to two images, for Keyman 3.2 keyboards)
language	Obsolete* (was the Windows system language for the keyboard)
layout	Obsolete (was the Windows system layout for the keyboard)

*In Keyman 6.0, the LANGUAGE header has been reintroduced, but with a different meaning. See The LANGUAGE Header for more information.

In Keyman 4.0, the "+" character became required, and usage became stricter to follow the standard now: the plus character must separate context from keystroke in a rule.

Other keyboard file history information will be added here as it becomes available.