**The Free On-line Dictionary of Computing (18 March 2015):**

dot notation
Berkeley Unix notation for an Internet
address, consisting of one to four numbers (a "dotted quad")
in hexadecimal (leading 0x), octal (leading 0), or
(usually) decimal. It represents a 32-bit address. Each
leading number represents eight bits of the address (high byte
first) and the last number represents the rest. E.g. address
0x25.32.0xab represents 0x252000ab. By far the most common
form is four decimal numbers, e.g. 146.169.22.42.
Many programs accept an address in dot notation in place of a
hostname.
(2000-08-10)