On Acord 35 - cancellation request. Does the reason the Insu

I was told by a competing agent that the reason why the insured was cancelling had to be placed in the remarks section and that just checking the box "requested by Insured" was not adequate. They claimed this was per the State Bureau of Insurance. I have scoured the State Insurance Code and have found no reference at all relating to an Insured requesting to cancel a policy.
I think this agent is mad because the client doesn't want to do business with them anymore.