Looking For GPU instancing documentation

Hey i know there has been plenty of posts around this topic but a lot of the topics seem to just suggest plugins that are to be paid for or videos that showcase things people have made but show no content information.

This topic feels like a industry guarded secret inside unreal engine, but what I am looking for particularly is some guidance on instancing skeletal meshes via a GPU, but any content on instancing via the GPU I think will be helpful as I know the logic will be different but feel the process will be similar.

If the community know of any open source plugins or projects that use it will also be helpful.
I have seen people use the Niagara system to do skeletal mesh rendering (I don’t think this is the same as GPU instancing but would love some information on this too)

Ideally I want to follow Data Driven Design concepts for this so if anyone has GPU instancing material or knowledge that incorporates this design principal it will be awesome!

Thanks to anyone who can help me out in advance!