Automatic Additional Insured

It may sound like when you name an android as your insurance beneficiary. But in reality it relates to clause in some insurance contracts that automatically extends coverage to other entities, without those other entities having to be named in the original policy.
It often comes up when one company contracts for a job (say a construction project) and then subcontracts a part of that work to someone else. It would be a pain to name all subcontractors individually in its insurance policy, or go back and amend the policy each time a new subcontractor comes on board.
So, instead, the original company would have a clause in its insurance that automatically extends coverage to these other companies, as long as the proper conditions are met. These conditions would be laid out in the original policy. Also, the extension of coverage would often get mentioned in the contract signed between the two parties.
This way, there would be no need to go back and revise the original policy - signing on for the job automatically extends the insurance.