Octal Wikipedia
The octal numeral system, or oct for short, is the base8 number system, and uses the digits 0 to numerals can be made from binary numerals by grouping consecutive binary digits into groups of three (starting from the right). For example, the binary representation for decimal 74 is . Two zeroes can be added at the left: (00)1 001 010, corresponding the octal digits 1 1 2 ...