IBM 3270 Operator's Manual page 118

PAl and P A2 Keys
On the 3278 Typewriter/Text keyboard, PAl and PA2 can be activated only
in Non-Text Downshift Mode and Text Downshift Mode.
Tab Key
The Tab key operates normally in both Non-Text (Downshift and Upshift) Mode
and Text (Downshift and Upshift) Mode. When the Tab key is pressed with the
ALT key held down, the
m
symbol is displayed and tabbing is not done.
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