Amounts to be added to ("arbitraries") or subtracted from ("differentials") base rates may be published either directly with each point or in an item referred to directly with each point. Provisions governing arbitraries or differentials which differ from those governing the base rates shall be referred to directly with the arbitraries or differentials (see Section 1225.505 ).
Ill. Admin. Code tit. 92, § 1225.1710