RFC 790, далёкий 1981 год (я ещё в школе учился):

Код:
....

   Assigned Network Numbers

   Class A Networks

....

      037.rrr.rrr.rrr   DECNET        Digital Equipment Network    [DRL]
      038.rrr.rrr.rrr   DECNET-TEST   Test Digital Equipment Net   [DRL]
Ну и для того, что бы понять масштабы тогдашнего интернета:

Код:
   Class B Networks

      Internet Address  Name          Network                 References
      ----------------  ----          -------                 ----------
      128.000.rrr.rrr                 Reserved                     [JBP]
      128.001.rrr.rrr-128.254.rrr.rrr Unassigned                   [JBP]
      191.255.rrr.rrr                 Reserved                     [JBP]

   Class C Networks

      Internet Address  Name          Network                 References
      ----------------  ----          -------                 ----------
      192.000.001.rrr                 Reserved                     [JBP]
      192.000.001.rrr-223.255.254.rrr Unassigned                   [JBP]
      223.255.255.rrr                 Reserved                     [JBP]