If players have multiple base cards in the same set, I consider them both rookie cards. A perfect example is 2001-02 Upper Deck. All the first round draft picks had a short printed subset Star Rookie card in series 1. In series 2 they had regular base cards, not part of the Star Rookie subset. Yet, the hobby (Beckett) considers the series 1 cards RC cards and not series 2...even though by the rules they made up a subset card cannot be a RC.
Personally, I'd rather have the series 2 cards. A game action shot always is better than a suit or summer league shot. And those are better than college shots.
I don't tag a true subset as an RC, like in 1992-93 Upper Deck. Although they are issued in the rookie year, they are their own separate thing. I have a column set aside in my Excel files for denoting subsets or RC.
Personally, I don't consider it a RC unless it was actually issued in their rookie year. For instance...Darrel Armstrong entered the NBA in 1994-95. His first card was 1996-97. Beckett, COMC and here list that as his rookie card, but in my collection records he does not have a rookie card. Unfortunately, because panini decided to be stupid, it means that NONE of the 2011-12 rookies actually have a rookie card.
The RC designation is important because I'm documenting the history of the sport. Denoting an RC on a first year player's base cards allows me to see easily when a player entered the league. With stars, I generally know that. With guys who didn't make it, or guys who entered the league in a time period I was not watching, it prevents me from having to go look it up. And my collection is over 3000 NBA players alone. I can't remember all that information. For players who I have a lot of, it helps me keep track of what I need vs. what I have. For example, my all time favorite player, Elton Brand, I know I need three of his RC left to have them all. I can simply select all his cards in my Excel chart, sort by the Note column, and see exactly which ones I have.
Especially for the players who entered the league in 2007 through 2010, it helps me keep track of my progress in getting the cards I missed out on when I was away from the game. That progress is slower than I'd like but hopefully someday I'll be able to correct my mistake.
VERY slow trading due to health problems. Not transferrable so safe to trade with, just moving is painful and can't always access the cards.
Cardboard History My COMC
New Collection Website: Cardboard History Gallery (Still under construction)
Tips on how to make your scans look like the card does in hand (No more washed out, fuzzy scans!):