User blog comment:Checker Fred/Season 2 was never split, iCarly season 6/@comment-3048370-20120114130219

Broadcast Season (The way Nickelodeon calls them)

Season 1: iPilot - iHave a Lovesick Teacher (25 episodes)

Season 2: iSaw Him FIrst - iFight Shelby Marx (25 episodes)

Season 3: iThink They Kissed - iBeat the Heat (20 episodes)

Season 4: iGot a Hot Room - iLost My Mind (14 episodes)

Season 5: iDate Sam & Freddie - ???

Production Season (The way they really are)

Season 1: iPilot - iCarly Saves TV (25 episodes)

Season 2: iGo to Japan - iBloop (45 episodes)

Season 3: iGot a Hot Room - iParty with Victorious (13 episodes)

Season 4: iLost My Mind - iToe Fat Cakes (11 episodes)

Season 5: (Starts production soon)

If you ask me, I think the episodes should be listed in their production order rather than their broadcast order.