Ive had level 10 sovas before. They only had 6 fighter squads. Dont know where your getting 7 from.

I stayed at a holiday inn express last night

Well, from the downloaded client I bought a week or so ago, it says...
"Squadrons Supported: 2 (upgradeable to 7)"

Yeah, my manual says 7 as well.

Never noticed before, but the sova gets one more squadron than the other races carriers....

I guess you could take a look at the mod files to confirm...

Typo in the manual/old information then? Or unintended outcome?
Could a Dev possibly elaborate?

I think Sovas should carry more birds. Six squadrons is the maximum. I could build six light carriers for less credits than a Sova costs, and then not even have to level them up. Battleships carry a scary amount of weaponry compared to frigates and cruisers; carriers ought to house a scary number of squadrons compared to light carriers.

...and what special ability are we missing?

No the advent have an ability that let the defense hangar squadrons have an additional 2 strike craft per squadron. The Advent carrier has a passive ability that lets each squadron have 3 extra craft at level 3.

And the guy saying there's an ability to let the sova have an extra squadron, I think thats actually the advent carrier's ability (maybe vasari's as well)

That was probably just a guess.

Sova special abilities are:
- Rapid Manufacturing (instantly reproduce fighters)
- Heavy Fighters (gives fighters armor and damage upgrades)
- Embargo (steals income from enemy planets)
- Missile Batteries (creates a separate temporary structure that fires missiles, much like a turret)

Nothing resembling a 7th ship squadron. Maybe the 7th port is used to release the missile battery?

I just chalk it up to old information that might have previously been targeted for the game design but was removed and the manual not updated. Given how badly out of touch many game manuals are by the time the game is released to the public, this difference is pretty minor.

-- Retro