ddddddB, where d is any octal digit
You can use the letter B or b.
There can be 1 to 11 octal digits (0 through 7).
11 octal digits represent a full 32-bit word, with the leftmost digit allowed to be 0, 1, 2, or 3.
Each octal digit specifies three bit values.
The last (right most) digit specifies the content of the right most three bit positions (bits 29, 30, and 31).
If less than 11 digits are present, the value is right-justified—it represents the right most bits of a word: bits n through 31. The other bits are 0.
Blanks are ignored.
Within an I/O format specification, the letter B indicates binary digits; elsewhere it indicates octal digits.