Without further ado, the following was found: Issue: I<%\\[aq]F> → I<%F> ? "For decimal conversion (B<i>, B<d>, B<u>, B<f>, B<F>, B<g>, B<G>) the " "output is to be grouped with thousands' grouping characters if the locale " "information indicates any. (See B<setlocale>(3).) Note that many versions " "of B<gcc>(1) cannot parse this option and will issue a warning. (SUSv2 did " "not include I<%\\[aq]F>, but SUSv3 added it.) Note also that the default " "locale of a C program is \"C\" whose locale information indicates no " "thousands' grouping character. Therefore, without a prior call to " "B<setlocale>(3), no thousands' grouping characters will be printed."
