Wait, I thought it was a simultaneous firing?! Though since the new Shepards of the Halo Franchise have proven themselves to be pants-on-head incompetent, the lore of Halo now seems to be worth less than the spit wasted taking about it.

IIRC the number is the order it was built (like a serial number) and the greek letters were specifically the order they would have fired when triggered from the Ark. Each ring could also be triggered individually, which would break the 'designated' order.

You're farther in than I am. My buddy and I just ran all of 1, 2, and 3 and feel like we know the bare basics of what's going on. I also now understand why Halo 3 was such a big deal after the cliffhanger in 2. Neat stuff.

It’s been a while since I’ve gotten in the lore of Halo but my guess would be “hey passing by or living in proximity to this particular massive life destroyer 9000 ring is ok because this one has fired and cleared it’s part of the galaxy/system”. Probably a way to categorise which areas have had their rings triggered for traversal or flood surveillance. Like if three rings fired and each one was successively closer to a forerunner installation it could potentially be a form of early warning. Since all the Halos can be accessed/fired remotely from the Ark which was a forerunner repository of all sentient life. That said, rule of cool is a thing and delta halo does sound cooler than 04.