What does this mean? What are some examples?

Because someone with good rebounding position can be backed out of their spot and I don't ever see anyone calling an intentional foul.

What you are talkin about is a foul, but not an intentional foul. I'm assuming, which is usually a mistake, that your thinking that this is an attempt to neutralize an obvious advantageous position. You will be hard pressed to call a rebounding situation an obvious advantageous position, thats pretty much a normal play.
Most of the intentional fouls I see involve two handed pushes from behind on a player making a layup or situations involving what the talking heads call a "hard foul" when the defense is not playing the ball.

Basically, what it is referring to is a foul taken to purposely stop an opponents break-away and easy basket. What the NBA calls a clear path foul.

Where the calling of the foul in itself stops the action, thus taking away an irreversible advantage. Example, clear break to the basket, foul in the back. Here's one I called in my first year. Coach had a hernia, but I knew I was right, and so stuck to my guns. I remember it clearly, because it was one of only about 3 calls I got right my whole first year.

Girls' freshman. Team A way better than Team B. But B gets a defensive rebound, quick outlet pass to B2, A2 who should be on defense is between the sideline and the ball and can't get inside position to stop the drive. Just as B2 cuts to the basket, A2 reaches out and bumps B2 in the side, and not even enough to throw off B2's rhythm. I thought it was an obvious intentional.

You should start to get a good idea from some of the above responses...

Your rebounding scenario would not be considered an intentional, unless the fouler is getting violent.

What I have seen and consider intentional is defense from behind the dribbler during his break to the basket. The dribbler has beat his defender and headed toward the basket... now the beaten defender grabs an arm, or shirt, or pushes from behind to knock the dribbler off balance... intentional. Two shots and the ball back - even if the dribbler gets a shot off and it goes, still two shots.

Called one to end last season that got the coach way excited... tight game, less than 10 seconds left, his team is behind, he has the ball but his guard cannot get the entry pass into his star post/forward player at the free throw line. After some very good and determined defense, a pass is made. Defender gets two hands on the pass, his player's arms are around the defender's arms. His player throws his arms to the side (and I judged it to be intentional), defender gets thrown to the floor with the ball. Foul had to be called. I called intentional. The defender gets two shots on the other end - misses both. Ball out where the foul occurred - they throw 3/4 length and the ball goes out untouched. His team now gets the ball back in their front court - free throw line extended to the sideline. They still blow the opportunity and fail to score.

Game is over. I'm feeling good like I just made a great, and needed call. Now the fun starts.

My partner lets the coach into our dressing room while I'm in the shower - what and absolute idiot! The coach wasn't too brilliant either, but my partner should have been shot! Coach feels it was my fault that they lost because I called the intentional foul. ... wait a minute coach, it was only because I called an intentional foul that you got the ball back in your own front court. The foul had to be called - your player knocked the defender to the ground with the ball. It was gong to be a two shot foul no matter what. If I had not called an intentional, you would have probably had the rebound underneath their basket rather than getting it back in your front court. Calling just a regular foul, as you wanted, would have been worse for your team!

Go figure! :D

Waaaahooooo! My season starts this Friday!

Let's not be too quick to say that. What cford asks does have some solid basis in the rules. After I gave my initial and perhaps too quick answer, I did a little research on this question and found the following:

4.19.3 Situation C: Team A leads by three points with four seconds remaining in the fourth quarter. Team A is to throw-in from a spot out of bounds on the end line. Players begin jockeying for positions just after the official has handed to ball to A1. B1, while trying to deny a pass from A1 to A2: (a) grabs A2's arm; or (b) pushes A2 from behind. RULING: In (a) and (b), it is an intentional personal foul designed to keep the clock from starting or to neutralize an opponent's obvious advantageous position.