"In all matches, either player may insist on the use of an electronic clock, if one is available"
I believe this to be a very handy rule as I prefer to use my own DGT XL clock rather than some of the knackered old junk some clubs still use.
In particular, I dislike the GARDE style clockwork clocks which I find annoying to use in a time scramble. The flag drop point is difficult to judge.
Anyway, I wonder if other leagues allow one to use their own clock?