specifies the list form of MSGDISP. This generates a parameter
list that contains no executable instructions. The list can be used
as input to and can be modified by the execute form.
TXT={'msgtxt'|addr}
'msgtxt'
specifies the 1- to 6-character text. The text must be enclosed
in apostrophes.
addr—A-Type address
specifies an in-storage address of an area containing the text
to be displayed.