A rule of thumb that usuallyapplies: The prefix indicates manufacturer and the suffix indicates a package type. Be sure to check datasheets to be absolutely sure, though. For example, with the LM386, the LM386N-1, LM386N-3, and LM386N-4 all have important differences in electrical specs. So it's not always the case that different suffices are functionally equivalent. With the TL072, though, the difference between the 'IP' and the 'CP' suffix comes down to operating temperature specifications and can largely be ignored for our purposes. Also, sometimes the suffix indicates how something is packaged (e.g., ammo pack, bulk, tape/reel).