You can either specify common companion specifications in the namespaces array by specifying the namespace alias, which makes it easy and compact.

Look at the table below to find the list of pre-defined namespaces aliases.

Example:

namespaces: 
    - di
    - machineTool
    - woodworking

Alternatively, you can specify more explicitly the namespace URI.

namespaces: 
    - di
imports:
  - uri: http://opcua.org/UA/MachineTool/
    alias: machineTool
    filename: ./machine-tool.xml

Note: make sure your alias is unique and does not conflict with the pre-defined aliases.

common namespaces aliases

namespace Uri	alias
`http://opcfoundation.org/UA/`	ua
`http://opcfoundation.org/UA/DI/`	di
`http://opcfoundation.org/UA/ADI/`	adi
`http://opcfoundation.org/UA/IA/`	ia
`http://opcfoundation.org/UA/AutoID/`	autoId
`http://opcfoundation.org/UA/CNC`	cnc
`http://opcfoundation.org/UA/CommercialKitchenEquipment/`	commercialKitchenEquipment
`http://opcfoundation.org/UA/Machinery/`	machinery
`http://opcfoundation.org/UA/Robotics/`	robotics
`http://opcfoundation.org/UA/MachineVision`	machineVision
`http://opcfoundation.org/UA/PackML/`	packML
`http://opcfoundation.org/UA/MachineTool/`	machineTool
`http://opcfoundation.org/UA/Woodworking/`	woodworking
`http://opcfoundation.org/UA/Eumabois/`	eumabois
`http://opcfoundation.org/UA/Glass/Flat/`	glass
`http://opcfoundation.org/UA/IJT/`	tightening
`http://opcfoundation.org/UA/GDS/`	gds