where in nec does it say you have use a pvc connector at the end of a pipe in the ground fed with uf?

is this a wives tale. 300.4 apply?
and the wire is smaller then #4 so the only bushing requirement doesnt apply.

i always do it(trained this way) but wonder if i have to.

h20

How about 300.5 (H) Bushing. A bushing, or terminal fitting, with an integral bushed opening shall be used at the end of a conduit or other raceway that terminates underground where the conductors or cables emerge as a direct burial wiring method. A seal incorporating the physical protection characteristics of a bushing shall be permitted to be used in lieu of a bushing.

Could this be it?

this 300.5 must be it....
thanks

h20

Also 300.15(C)