  >< T - S P A C E S   P E R   T A B ><

Specifies the distance between tab stops in a file in which spaces are
compressed to tabs.
 If "fm +l" is asserted, this number will be used to expand leading tabs to
spaces on reading, and to compress leading spaces to tabs on writing.
 If "fm +tr" is asserted, this number will be used to expand tabs to spaces.
 If "fm +tw" is asserted, this number will be used to compress spaces to tabs.
However, because Q has no idea where tabs were originally, if there is a choice
between outputting a single space or a tab, Q outputs a single space. You
should assert "fm -t -l" if you need to preserve tabbing.

The default value of tab stop spacing is 8.
