It's almost never that simple. For example, a (regular) telephone book cannot be copyrighted[1] but medical billing codes for insurance can be[2] (so far.)

[1] Feist Pubs., Inc. v. Rural Tel. Svc. Co., Inc. - 499 U.S. 340 (1991) http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=us...

[2] Practice Management v AMA - 121 F.3d 516 (9th Cir. 1997) [writ denied by SCOTUS] http://cyber.law.harvard.edu/people/tfisher/IP/1997%20PMI%20...