[nickerous]

I've got two different Super Punch-Out carts for the SNES. One has an ESRB image on the cart label. It also has these markings on the label:

SNS-4Q-USA-1
Made in Japan

The other one does not have the ESRB image and has these markings:

M/SNS-4Q-USA
Made in Mexico

The first one is boxed and the box also has the ERSB image on it. I had this back in the SNES heyday and don't remember the box having the ESRB on it. Would this be a re-release? Second release?

[Deadguy2322]

It is most likely the Mexican release. Some games for the SNES were actually given market-specific releases in Mexico, which is also where the insanely rare English NTSC version of International Superstar Soccer 2 comes from.

[KingMike]

Also, Super Punch-Out!! was released in October 1994, just before the ESRB ratings came into use (November 1994).
Possibly the other one is a later printing or re-release to reflect that.

(and my cart is SNS-4Q-USA, Made in Japan, no rating)

[BMF54123]

Well, I can tell you that the one without the ESRB rating came out first. The second one might be a Majesco rerelease. Check the warning text on the back of the cart; if it's molded into the plastic, it's a Majesco cart (they were made in Mexico and packaged with black-and-white manuals to save money).