Balk or bad mechanics?

[umpduck11]

Originally posted by SAump
.

His mechanics must be consistent throughout the game, or it could, by rule, be a BALK.

Please tell me where in 8.05 this is mentioned.
I've read it twice, and fail to see any mandate
that the pitcher must do this.
Which "rule" is he violating ?

[Edited by umpduck11 on Feb 19th, 2006 at 10:08 AM]