Lawyers nowadays use the term in the sense of a writing or document, signed and sealed and delivered to a 3rd party, for them to hold it pending the occurrence of a subsequent condition, when it is then released to the obligee. Hence the origin of signed sealed and delivered, ie delivered to the obligee. In software the source code is often held in escrow by a trusted 3rd party to be released to the licensee upon fulfilment of certain conditions.
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