Thev are all initially set to 1.
be used to communicate between different recursion levels of the
determine the number of active arguments in the
and test it.
buffer (console stack) &READFLAG contains the value
read request results in a line being read from the stack. If not, then
the next read request results in a physical read to the terminal, and
the value of &READFLAG is
variable but you can examine and test it.
numeric values (positive or negative), and is set after each
changing it is not recommended.
(resume typing) or
terminal display has been suppressed by the Immediate command
contains the value RT when the terminal is displaying output.