%O a synonym for %lo
%F a synonym for %f
-Conversions to scientific notation by C<%e>, C<%E>, C<%g> and C<%G>
-always have a two-digit exponent unless the modulus of the exponent is
-greater than 99.
+Note that the number of exponent digits in the scientific notation by
+C<%e>, C<%E>, C<%g> and C<%G> for numbers with the modulus of the
+exponent less than 100 is system-dependent: it may be three or less
+(zero-padded as necessary). In other words, 1.23 times ten to the
+99th may be either "1.23e99" or "1.23e099".
Perl permits the following universally-known flags between the C<%>
and the conversion letter: