Section 3.5 (p. 167 ff.): The switches are called flags; and the
ON/OFF procedures are documented. The essential idea with
introducing all the SET/GET variants of them was to avoid this.

The reason is, that sometimes the actual mode change is or may
become performing some procedures redefinition, but ACCOMPANIED
by a switch being turned on or off. If you just change the
switch, you may get very curious errors, in such cases.


p. 212 (the index): "degreeeddisplay" is a misprint for
"degreeenddisplay", and should be grouped with the latter.
(Probably an erroneous reference in the source file corresponding
to p. 118)