[RTTY] CAP letters on or off?

[David VE3VID]

Sorry about the simple type question.  I'm a bit confused by something I read a while back.  Should I have my computer keyboard CAPS LOCK set on for RTTY?   Otherwise avoid shifting between upper & lower case letters?
 
Thanks for the help
David

    VE3VID          
Located in rural Canada
Solar power.  Wood heat.
Mosley tribander @ 22m
2element delta-quad on 40m
Lots of space for dipoles,
bears and wolves......73

http://www.ve3vid.webs.com/