What exactly does it mean to complete inside $'...' anyway?

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

It occurs to me I have no idea what is intended to happen in the case of

% : $'<TAB>x

for any particular values of "x", which might be e.g. $'\07' or $'\M-x'.
Same goes for

% : $'<TAB>x'

or even

% : $'x<TAB>'

the latter of which doesn't produce any debug warnings but doesn't seem
to do anything helpful either.

-- 
Barton E. Schaefer