Yeah, it was the PA. Here's the announcement from 2005, recall reading this once before but didn't really pay it much mind. Didn't relize it was that long ago.
Major League licensor clears up major confusion
Previous definition of "Rookie Cards" misleads consumers and discourages baseball card purchasers
MLB Players Association
Responding to consumer confusion concerning the definition of a Major League rookie card, the Major League Baseball Players Association Thursday warned consumers to look for the Major League Baseball silhouetted batter logo and the Major League Baseball Players Association Players Choice logo on trading cards in order to determine whether the cards are officially licensed. As of 2005, the valuable Major League logos are authorized to appear only in connection with trading cards featuring players who have at least one day of actual service on an active Major League roster.
Many trading cards are published each year containing the names and images of athletes who are Minor League players or draft picks. In the other major sports, trading card manufacturers are prohibited from including Minor League or draft pick players in their officially licensed trading card sets, and a player's official "rookie" card is published only in the year of his professional debut. In baseball, however, manufacturers have been permitted in the past to commingle Major League and non-Major League products in the same packages and until this year, the licensors have authorized their logos to appear on the cards, thereby making them "officially licensed" products. This has resulted in the trading cards of minor league players--many of whom will never become Major League rookies--being widely perceived as "rookie cards," which are valued more highly in price guides than other cards of the same player.
There's a bit more, and this is where I got that info from:
http://mlb.mlb.com/pa/releases/releases.jsp?content=0512b
The Trevor Story cards have been cause for some debate this season too with him starting off hot, and his Topps Now cards in the mix aslo.
"I believe there ought to be a constitutional amendment outlawing Astroturf and the designated hitter." - Crash Davis