sealed instrument
contract under seal
special contract

Last I heard he was workin' under a special contract or something.

There are no special contracts in this game.

Other local and state governments occasionally enter into special contracts with security agencies to provide patrol services in public areas.

But part of the law says that if the Government has a real need for a certain product it can issue a special contract.

These special contracts are more or less obligatory and must be fulfilled.

The rate of interest upon a special contract may be, and often is, high.

They were probably recruited through special contracts and likely received some privileges compared to the native Bulgarian population.

This has happened despite the Chinese central bank's efforts to buy back extra yuan through the sale of special financial contracts to banks.

After the performance, they take Ash aside and offer him a special contract - a solo deal.

Various types of special contract, such as employment or insurance contracts, are therefore dealt with separately.