Major thanks to Jeff Maeda at COMC! If I'm not the most annoying seller when it comes to card identification, I'm probably in the top five. And while I may have issues with what they will and will not include for sale on the site, I have to say the customer service is superb. The one Japanese card that was going to be returned due to identification issues is now listed in my inventory.
That said, it should be noted that probably 90% of the baseball cards listed as belonging to 1990 ProCards team sets (with the wood grain) are actually from the 1990 CMC Pre-Rookie set. The main differences being, the ProCards are not glossy, don't have the extra little card number in the lower right corner on the back and usually have some sort of local sponsor's logo on the back under the stats.
Ditto for the cards listed as belonging to the 1990 CMC team sets. The team set cards have green backs. The 1990 CMC Pre-Rookie cards have yellow backs.
In both cases, the team set cards almost always have a higher book value with the CMC Pre-Rookie cards being almost universally commons, which is skewing the valuation of these cards on the site.