The %m and %d directives support the #, 0 and + flags, but the other directives do not, even if they print numbers. Numeric directives that do not support these flags include
G, U, b, D, k and n.
All fields support the format flag -, which makes fields left-aligned. That is, if the field width is greater than the actual contents of the field, the requisite number of spaces are printed after the field content instead of before it.