Deep within the graphic data of the original Mega Man Zero, something interesting was uncovered by Cutting Room Floor member xdaniel. Apparently, the game might have once featured the ability to trade Cyber Elfs, presumably with other players:
An unused tab reading "Elf Trading" in katakana can be found within the game's menu graphics (bottom left). This feature is not present in the final game, and any traces of its functionality are non-existent.
Cyber Elfs play an integral role in Mega Man Zero; special power-ups that enhance the player's abilities or alter stage conditions. Trading Cyber Elfs probably wouldn't have had much, if any affect on gameplay. I imagine the feature would've brought a social aspect to the game, sort of like trading chips in Mega Man Battle Network.
It's funny now, but I remember when Mega Man Zero released there was considerable demand among players for an Elf Trading feature. Ten years later, we're looking at solid proof Capcom once considered the prospect. I wonder why they removed it?
Interesting find, to say the least.
Source: Jul -- Cutting Room Floor