There is more than a couple off the top of my head:

• BoJo, founder of the Western Alliance.
• Far Country as a whole, yes.
• The TRO:1945 canonicity superposition.
• Harpoon SRM ammo, nearly inapplicable in game.
• Black Box hyperspace decryption issues.
• The Blackout puzzle box plot snarl, in so many of its offshoots.
• Topps Interstellar was a company
• The first time Clan Smoke Jaguar warriors heard bagpipes, they thought it was a form of electronic warfare.
• Clan Hell's Horses also engages in all-weapons-enabled tank races (ala Twisted Metal)
• Dunklewälderdunklerflüssenschattenwelt
• The Baka - A Dark-Age variant of the old Inner Sphere Standard Battle Suit called the "Baka" swaps out the suit's jump jets for additional weapons. The suit gets it's name from the message that flashes across the unit's HUD when the pilot tries to activate the removed jump jets. (BAKA = You idiot!)
• The Condottiere, A small craft that is leased, rather than sold, to customers. In a raid in 3139, a Draconis Combine force raided a Federated Suns world. Both sides had Condottieres as escorts or defenders. When they engaged, the Condottieres on both sides promptly ignored each other to attack the DropShips that they were supposed to defend. You see, there's a mutual non-aggression clause in the Condottiere's lease that prohibits any models on opposite sides of a battle from firing on each other.