Sleeving SER cable through PVC

[T74]

I've seen SE cables sleeved through PVC plenty of times but I've never done it. I have an underground PVC conduit from a house to a barn where sleeving SE through the pipe would be a lot easier for different reasons.

What's the deal? Is it code?

 

[infinity]

Easier or not you cannot install SE cable in an underground raceway.

338.12 Uses Not Permitted.(A) Service-Entrance Cable. Service-entrance cable (SE)
shall not be used under the following conditions or in the
following locations:
(1) Where subject to physical damage unless protected in
accordance with 230.50(B)
(2) Underground with or without a raceway