Thanks, Randal. Yes, of course you are right. I would have done better to put my post in the form of a question. (E.g. "but this seems to work, please explain... etc. etc.")

And your explanation makes clear why I have gotten away with this with known keys that happened not to be any of the 100 or so named HTML entities.

The fact that my suggestion works much of the time makes it all the more dangerous -- since it will lead to complacency and a rude awakening down the line.

I did say "considerable trepidation". Perhaps there is solice in the thought that this exchange will be instructive to others. <brave grin>