[GENERAL] Schemas and foreign keys

Recently I asked regarding schemas, and received very useful answers. I
conclude that I can put some tables in one schema and left others in the
public one.
If my app selects some schema, the backend will found automatically the
absent tables in "public".
So far, so good.
But what about foreign keys? At least, I will have foreign keys from the
tables in the specified schema to the tables in "public", because I'm
thinking that the tables in "public" would be references, while the
tables residing in the specified schema will be the transactional ones.
TIA
Marcelo