quick designation question

[tdowning]

I'm just looking to know is there a consensus on the identification of MacBook Pro chassis(es)

First gen chassis was stamped
Second gen was Unibody with with the 2 panels on the underside
Third Gen was the "non user replaceable battery
Fourth Gen is Retina (and no optical)

Is there an any official way to distinguish a second gen from a third gen?
Did the third gen coincide with expresscard/34 being removed in favor of SD, therefore, breaking out as: Stamped, Unibody ExpressCard, Unibody SD card, Retina?

I've looked on MacTracker, and don't see any distinction recorded there for swappable batteries.

 

[Dew]

From Wikipedia:

During the MacWorld Expo keynote on January 6, 2009, Phil Schiller announced a 17-inch MacBook Pro with unibody construction. This version diverged from its 15-inch sibling with an anti-glare "matte" screen option (with the glossy finish standard) and a non user-removable lithium polymer battery. Apple affirmed the battery's design was unlike any existing notebook battery. Instead of traditional round cells inside the casing, the lithium-ion polymer batteries are shaped and fitted into each laptop without wasting space. Adaptive charging extends battery life, which uses a chip to optimize the charge flow to reduce wear and tear. Compared to the previous iteration, battery life for the 17" version is quoted at eight hours, with 80 percent of this charge remaining after 1,000 charge-discharge cycles. This battery is not intended to be user-removable.

At Apple's Worldwide Developers Conference (WWDC) on June 8, 2009, it was announced that the 13-inch unibody MacBook would be upgraded and re-branded as a MacBook Pro, leaving only the white polycarbonate MacBook in the MacBook line.[39] It was also announced that the entire MacBook Pro line would use the non user-removable battery inherited from the 17-inch MacBook Pro.

The Wikipedia article is pretty detailed and disagrees with the notion of four generations.


What this leaves us with is the only MBP that ever had a removable battery was the 15" MacBookPro5,1 (Late 2008/Early 2009).