[my_pointy_head_is_sharp]

I'm still reading about this. Your link is especially interesting - the siglas (which I'd never even heard of), his lack of a signature (he never signed his name, ALWAYS used a sigla), the fact that he never wrote in Italian (always Spanish or Latin), his monogram, the papal bulls - all of this is fascinating.

I've been googling for more information. Here are two more interesting sites:

Was Christopher Columbus a Jew?

Christopher Columbus - Mythbusters is halfway down the page

I also read that the "Majesties" of Spain had called for all Jews to be expelled from Spain. Perhaps in the climate of the times, Columbus felt compelled to hide his Jewish identity (if he indeed was Jewish).

The Vatican, also, is withholding quite a bit of information from the public re Columbus.

[ValerieUSA]

The Nina, the Pinta and the Santa Maria sailed out of Spain on the same tide that carried the last of the Jews and Moors (Muslims) from Spain before their presence was outlawed in the kingdom.

[4CJ]

Why a "trade" name?