Later this year, DC's big event will be something called Infinite Crisis, which supposedly will be a universe-altering event, similar to the Crisis on Infinite Earths that they did back in 1985. For those who don't know much about Crisis, a little detail follows.
In the 1950s, DC Comics began to introduce new versions of their Golden Age characters, starting with the Flash. Eventually, it was decided that these new versions of their characters lived in an entirely different universe, which they named Earth-1. The original superheroes lived on Earth-2, where time moved more slowly. Having two different universes was a good way to avoid continuity problems between characters.
It was also a good way to accomodate other characters. For example, when DC bought Fawcett Comics and the Marvel family of heroes (the ones who shout "Shazam!"), they placed them in their own universe, Earth-S. When World War II ended but Uncle Sam and the Freedom Fighters still wanted to fight the Nazis, they could do so on Earth-X. When DC wanted a set of evil villains who were analogs to the superheroes, they created Earth-3 for them. And so on.
Eventually it was established that this "Multiverse" consisted of an infinite number of universes, and in 1985 DC decided to do a little housecleaning. (I'm skipping a LOT of history here.) In a year-long event, the Crisis on Infinite Earths, a villain from an antimatter universe named the Anti-Monitor decided to destroy all the other universes. The final result of this universes-shattering event was that the Multiverse was destroyed, to be replaced by one universe with, they hoped, one continuity, supposedly making it easier for new readers to dive in.
Of course, problems ensued. The housecleaning wasn't perfect, so in 1994 DC was forced to revisit their reconstruction of the universe with Zero Hour. However, that event only lasted for a month and wasn't nearly as universe-altering as Crisis. Then, a few years later, they created the concept of Hypertime which seemed to imply that other universes were still "out there" but not as easy to reach. Now, the powers that be at DC Comics are building up to a new event, called Infinite Crisis, which is supposedly going to be just as universe-shattering as the Crisis on Infinite Earths that took place in 1985.
But here's the problem I see. Since 1985, comic book fans, writers, artists, etc. have referred to events as being either part of "pre-Crisis" or "post-Crisis" continuity. If this brand new event is just as calamatous, what happens to these terms? Will we have to deal with the unwieldy construction of "post-Crisis, but pre-Infinite Crisis?" And if someone says "post-Crisis" from 2005 onwards, what will that mean, exactly? To which crisis will the speaker be referring?
I have a solution, but it only works if the fan community decides in the end that Infinite Crisis wasn't that good. If that turns out to be the case, we can abbreviate it as "IC" and pronounce it "Ick." Then we'll have four designations of continuity:
Pre-Crisis (Before 1985)
Pre-Ick (1985-2005...hey, wait a minute...)
Post-Ick (2005-whenever they screw around with the universe again)
Anyone who cares about this minutae is welcome to discuss it more here.
For more information, here are links to the Wikipedia entries on:
Crisis on Infinite Earths