Ill. Admin. Code tit. 92, § 1225.255
a) When a new agent is appointed for a reason set forth in Section 1225.250 or when an alternate agent assumes the duties of the principal agent, the new agent, immediately upon receipt of necessary authority, or the alternate agent, upon death or disability of the principal, shall issue a supplement to each of the effective tariffs (bound or loose-leaf) issued by or which had been taken over by the agent superseded. The supplement shall bear on its title page no effective date, but shall contain a statement reading substantially as follows:
On and after (show here, in the case of a new agent, the date on which authorities are filed with this Commission; or in the case of an alternate agent, the date on which the principal ceased to act) this publication shall be considered as the issue of (show here name of new agent or the alternate acting as such).
h) Where joint-agent publications are involved in a take-over there are four major situations. In each situation the supplement must be one containing no other matter than that necessary to effect and explain the action. In every case the agent who issues the take-over supplement shall also amend the list of participating carriers, where ever it is shown, in an appropriate fashion.