(%b %e %E %f %F %g %G %x %X and %v) are equivalent and accept
both decimal and hexadecimal notation (for example: "2.3e+7", "0x4.5p-8")
and digit-separating underscores (for example: "3.14159_26535_89793").

Input processed by verbs is implicitly space-delimited: the
implementation of every verb except %c starts by discarding
leading spaces from the remaining input, and the %s verb