Well the consensus on the Capcom Unity board seems to be that it's something that you unlock after a certain amount of time or beating the game a certain number of times.
I really doubt that, though.
So again, 3 last theories:
1. Remember how the NES had the B, A, Start, and Select buttons? Possibly a code, there, when you see Bass' blueprints. That doesn't mean you GET Bass, just means it might be wanting a related input.
2. It's a secret input in the vein of the Hadouken/Shoryuken in Mega Man X and X2, perhaps unlocked after some excruciating dying or repetitive method that you couldn't possibly know unless you had a hand in making the game or had an unreasonable amount of luck.
3. It's a fake set of spikes hiding a room or tunnel.