I think you either have the 2nd or 3rd Ed rulebook.
Unit rules are ONLY in the codex in 4th. So go by the codex, but any codex you have will NOT be compatible with those rulebooks. So i'd advise either getting the 4th Ed book or waiting for 5th.
Dark Angels 1750 win/loss Record
Win - 23 (Belial helped wreck Ryan's puny Eldar)
Loss - 13 (Brice's Necrons wiped me)
Draw - 2 (The 13th hold out in alpha take and hold)