Specification of a non-zero, positive integer count (+n1
allows some implementors to continue their
practice of using a zero or negative value as a flag to trigger
special behavior. Insofar as such behavior is outside the
standard, Standard Programs cannot depend upon it, but the
committee doesn't wish to preclude it unnecessarily.
Because actual values are almost always small integers, no
functionality is impaired by this restriction.
It is recommended that all non-graphic characters be reserved
for editing or control functions and not be stored in the input
Because external system hardware and software may perform the
function, when a line terminator is received the
action of the cursor, and therefore the display, is
implementation-defined. It is recommended that the cursor remain
immediately following the entered text after a line terminator