R10:21.

When an engineer or manufacturer builds apparatus from designs supplied to him by a customer, the designs remain the property of the customer and should not be duplicated by the engineer or manufacturers for others without express permission.

[See Codes 14(b)., III.10.b. ]

Code is relevant when:

Engineer has a client
AND
Engineer uses designs supplied by the client

Code is violated when:

Engineer does not recognize that the designs remain the property of the client
OR
Engineer duplicates the designs without permission

Code is not violated when

Engineer recognizes that the designs remain the property of the client
AND
Engineer duplicates the designs with permission