The most common for underground feeders within a customer's installation is SWA (armored) cable. It consists of the individual conductors within an XLPE sheath, then a layer of steel wire armor, then a final XLPE sheath on the outside:
2-core is red, black. 3-core is red, yellow, blue 4-core is red, yellow, blue, black
All are available in the standard metric conductor sizes from 1.5 sq. mm. upward.
C-H, Over here, Neutral-Screened is invariably used as a medium for our U/G services. It saves having to muck around with putting a length of TPS in conduit, which in turn has to be de-rated. Sorry but I can't get a pic of a piece of N/Screened at the moment. Over here, this cable has an outer sheath of 3.2mm thick PVC and it can be buried direct, without further Mechanical protection, provided that it is buried at Regulation depth (600mm).
We have two main types in Canada. NMWU and ACWU. non-metallic wet underground, and armoured cable wet underground. The armour isn't needed after certain depths depending on the ground usage (driveway, road, etc.) Main supplies are usually single conductor in PVC conduit or ACWU ('Teck') which costs more. The non-metallic just has a heavier insulation than our 'indoor' NMD, non-metallic dry.