Is Secondary Supply only for the original owner of a resource?

[OxfordGuy3]

Can someone remind me, does a "Secondary Supply" source only provide supply for the original owner of that resource (assuming no other supply source is available), or can it also provide supply to an enemy that has captured that resource? What about if it's a liberated Secondary Supply source from a former ally that has surrendered (e.g. if Britain has liberated a French supply source)? Thanks!

[Platoonist]

As I understand it you won't get the full advantage of either a primary or secondary supply source that is not your own when the status of these sources is still at issue. In other words, whether the country has surrendered yet or just been occupied.

You receive a partial benefit while it is occupied in which those locations will provide the full occupied primary or secondary supply value, but it will not provide supply to any further resource locations until the nation they belong to surrenders. Once you achieve total conquest and that country surrenders, fully occupied supply rules kick in as there is no more dispute over the supply routes within the occupied and surrendered country. I think liberation has the same effect.