There were many Earths on the Multiverse.
So how do we deal with this, should we create a Multiverse or Earth Category?:
Yes. Definately.
I started to create a Multiverse entry yesterday, but didn't get around to it.
It's featured too prominantly in some stories to ignore. It will have to come up in some entries, and we'll need a link to it.
I
do think we should
avoid unneccessary references to earth-1 and earth-2 in the entries. For instance, don't go calling Superman "Superman I" when describing golden age events.
But when understanding the multiverse is critical to understanding a particular character or event then it needs to be dealt with.