Proper way to pack textures

Hey guys i want to know if there is some global convention on how to pack up textures into one another.
Right now im using this
colormask in Albedo,
Metallic in Roughness,
Emission in AO
opacity mask in normal map
im just wandering if there is some generic conventional way to do this used by some amount of studios.

They have this article. A new, community-hosted Unreal Engine Wiki - Announcements and Releases - Unreal Engine Forums

At the bottom they describe stuff in Texture Masks for how they pack the different maps into each component. I’ve been following this.

I’m not entirely sure what you mean by Metallic in Roughness, Emission in AO, etc… I’m guessing you meant you pack those textures together somehow.