You're probably right, Brian.
As it's 30 years or so since the first computer-based teletype
machines were introduced, perhaps it's just a matter of decades until
all NOTAMs are made legible. Weather reports won't need to be
abbreviated either, as the days of the 300 baud (even the new 1200
Baud) modem are numbered.
I may be wrong, but improving this information to make it easily
understood could add to safety.
Better have a meeting to consider forming a committee!
Jim

On Feb 26, 12:01*pm, Brian wrote:
* Why are security NOTAMs typed "caps lock", which seems a poor way to
communicate?

My guess is, it is a leftover from the days of teletypes that only had
capital letters.