It is not marked "Apple Gift Card" for anything in the Apple Store.
If you REALLY want the really truly correct answer to your question, go to the SOURCE of the card (iTunes) or where you want to try and spend it (Apple Store).
Or even online at the iTunes store - when you redeem the gift card all the rules appear - there is all sorts of infomration about using the value of the card at the iTunes store... NOT an Apple retail store.
The iTunes Gift Cards Terms and Conditions at Apple.com start with, "This card is redeemable only on the iTunes Store for the U.S. To redeem this card you must have an iTunes Store account, subject to prior acceptance of license and usage terms."
NOT the Apple retail store.
Then there is this:
For your convenience - I know it is tough to click on the link:
"iTunes Gift Cards and iTunes Gift Certificates can be used to purchase music, videos, TV shows, and audio books from the iTunes Store. At this time, iTunes Gift Cards and iTunes Gift Certificates are not accepted for online Apple Store purchases."