"This instrument is non-negotiable in form but may be pledged as collateral security. If so pledged, any payment made to the payee, either of principal or of interest, upon the debt evidenced by this obligation, shall be considered and construed as a payment on this instrument, the same as though it were still in the possession and under the control of the payee named herein; and the pledgee holding this instrument as collateral security hereby makes said payee its agent to accept and receive payments hereon, either of principal or of interest."
Ill. Admin. Code tit. 38, § 210.90