The Control flag (.) is placed at the left margin to begin a
string of DSR commands. When you want a period to be accepted as
a text character, you do not need to precede it with an Accept
flag (_) as long as the period is not placed at the left margin.
If you do need to have a period in the 0 character position
(and it is not part of a DSR command), you must precede it with
an Accept flag. Alternatively, you can use two periods at the
beginning of a line; the effect is the same as if you had used an