Earths 1 and 2
Supermanica is unique among superhero encyclopedias in our concept of Earths 1 and 2. We limit the continuity of the wiki to certain specific Superman-related titles published from 1938 to 1986 which are listed on the canonical sources page. Instead of working from continuity as it has been explained outside the books, we conceive of the universe as it is presented within these "canonical" comic books. Earth-1 and Earth-2 and what they mean are inventions from outside those books. We only incorporate facts stated within those issues.
For instance, if one were to actually sit down and read Superman issues 1 through 423 in one sitting, one would read about a single character named "Superman" whose continuity evolved around him but who was always one character who just had different adventures from month to month. It was never stated within the books themselves that the reader was reading about the "Earth-2" Superman nor suddenly about the "Earth-1" Superman. "Earth-2" itself was never mentioned in the books, nor even conceived of, until the 1970s. Only events or concepts that are mentioned in the comics themselves are part of this wiki. We are inside the books looking out, not outside looking in.
More info and discussion about this can be found here.
Please feel free to participate in the forum or to discuss these issues here. Do not hesitate to raise any questions or concerns you may have. Constructive contributions to Supermanica are welcome and appreciated.
Golden Age Superman Vs Superman of Earth-2
Although the Earth 2 Superman is portrayed as being the character who appeared in the comics in the 1940s, a number of differences exist.
Perry White first appears as Clark Kent's boss in Superman #7 in December 1940, although the Earth 2 Superman supposedly never met Perry until after Clark Kent became editor of the Daily Star in the early 1950s.
The Daily Planet first appears in Superman #4, Spring 1940, with George Taylor as its editor. In another discrepancy the Earth 2 Luthor is portrayed as red headed, but the bald version of Luthor first appeared in Superman #10, June 1941.
The 1940s Superman also seems to have had a power that the Earth 2 Superman lacks, the ability to use his "super muscular control" to contort his face into any form of disguise that he wishes. This power was first used in Superman #18 and continued to be used through the end of 1947.
Source: These guidelines were agreed to by members of the defunct SupermanThruTheAges website (discussion can be continued at SupermanFan.net)