Maybe it's not necessary, but I've always used the octograph ( Big Word!) on each line I wanted to "silence."
Usually what I do, if i want to turn off a light but retain the instruction for later use, is to put "comment(" in front of or on the line above the area I wanted to disable, and then close the parentheses on the line below (NOT the same line) the last line I want to cancel. I find that almost as reliable as deleting. This also works to disable dynamic brakes or a passenger view.
To quote an authority - me too.
I have experimented with the "#" character as a comment delimiter. Except for using it completely within brackets - i.e.
keyword ( values #comment )
I can't seem to get it to work reliably. I would be interested if someone "knows" how it is supposed to work in MSTS. It is certainly doesn't function as in UNIX.