Graham,

just so you know, many blind people use a "screen reader" to read aloud to
them what's on a computer screen, and it doesn't usually distinguish case.

You're "please don't shout!" is perfectly appropriate, but just so you get
your point across you may want to add a parrenthetical note (don't type in
all caps).

I'm blind and do this frequently enough that I'm quite embarrased about it
whenever it happens.

thanks for your response, as it may put me on to the solution of my
particular problem.

Chip