bug#69807: questioning automatic -i in multicolumn pr

[Douglas McIlroy]

Multicolumn options in pr imply option -i (tabification). The introduction
of tabs with physical rather than logical meaning makes output that is OK
for viewing only if you have correct tab stops, and is complicated for
further processing.  It caters for obsolete equipment--typewriters, on
which tabbing was appreciably faster than spacing.

As a wish-list item I propose abolishing implicit tabification. A second
choice (that doesn't buck Posix) is to provide an option to suppress
implicit tabification. At a bare minimum, document a workaround for the
inconvenient tabs, e.g. post-processing with pr -t -e.