The command line prompt on the computer in the hatch is a greater-than sign, a colon, and a cursor. It looks like this:
While not important to the story, it’s funny because it looks like an angry face.
The food found in The Swan station and airdropped in via resupply has the same series of numbers and letters on every item. Some research over at Lostpedia indicates that it may designate where the airdrop originated from (in this case, Nigeria). It’s also possible that it somehow denotes the location or operating number of the installation/island, though this is merely conjecture and has no supporting evidence.
While not exactly a revelation, watching Season 2 again confirmed my belief that the hatch was a very important installation on The Island and that the fail safe was not used earlier because the DHARMA Initiative wanted to study it rather than detonate it. They obviously felt that the risk of studying it was worth it and that the potential knowledge from the magnetic anomaly was more important than the safety of Island-/world-/overhead-travellers. The real question is whether or not the fail safe destroyed the hatch, or merely “moved” it, similarly to the finale of Season 4.