This part of ISO 13628 specifies requirements and gives recommendations for the design, material selection, manufacture, design verification, testing, installation and operation of subsea control, chemical injection, gas lift, utility and service umbilicals and associated ancillary equipment for the petroleum and natural gas industries. Ancillary equipment does not include top side hardware. Topside hardware refers to any hardware which is not permanently attached to the umbilical, above the topside hang-off termination.