"Superboy's origins start with Project: Man of Tomorrow, which is the Superman cloning project originally intended to recreate the Man of Steel. Due to the inability to replicate Kryptonian DNA, the clones' bodies degenerate after a short period of time. Upon Superman's death, the project is reinstated in secrecy in conjunction with Lex Luthor and Cadmus Labs to replace the fallen hero."
-from the Superboy's overview
The bracketted numbers seem to me to be annotations which are not found in the overview, therefore make me wonder if this wasn't simply cut and pasted from another site. The numbers don't really seem to serve any other purpose as it doesn't seem to account for two things that needed to happen to bring Kon-El to life.