Rental Commission paid by tenant

[Victor Saumarez]

There’s plenty of info out there that suggests landlords usually pay commission to Realtors who find and process rent applications. Can anyone explain the actual process? For example, does the tenant write two check; one for the rent and security deposit, and one to the Realtors office. I’ve come across the latter, where it seems the tenant is being asked to pay the commission on behalf of the landlord, which is then deducted from the security deposit and rent. Is this normal?