It doesn't say concealed specifically. Concealed carry licenses apply. Open carry licenses apply. ATF has even agreed previously that in states which require a permit to purchase a handgun, that permit to purchase would satisfy the Fed GFSZA requirement IN THAT STATE.
You can believe whatever you wish, but U.S. Supreme Court in
Consumer Product Safety Commission et al. v. GTE Sylvania, Inc. et al., 447 U.S. 102 (1980) stated: "We begin with the familiar canon of statutory construction that the starting point for interpreting a statute is the language of the statute itself. Absent a clearly expressed legislative intention to the contrary, that language must ordinarily be regarded as conclusive."
Then again, the U.S. Supreme Court in
Connecticut Nat'l Bank v. Germain, 112 S. Ct. 1146, 1149 (1992) stated: “In any event, canons of construction are no more than rules of thumb that help courts determine the meaning of legislation, and in interpreting a statute a court should always turn first to one, cardinal canon before all others. We have stated time and again that courts must presume that a legislature says in a statute what it means and means in a statute what it says there. See, e. g.,
United States v. Ron Pair Enterprises, Inc., 489 U. S. 235, 241-242 (1989);
United States v. Goldenberg, 168 U. S. 95, 102-103 (1897);
Oneale v. Thornton, 6 Cranch 53, 68 (1810). When the words of a statute are unambiguous, then, this first canon is also the last: "judicial inquiry is complete."
Rubin v. United States, 449 U. S. 424, 430 (1981); see also
Ron Pair Enterprises, supra, at 241.”
The meaning of the statute is clear. If it ever gets to the Supreme Court we will see if they rule contrary to their past holdings.