It's more typical for them to claim ownership of it, rather than to forbid it. Any job where you have to submit a list of prior work with your employment contra

It's more typical for them to claim ownership of it, rather than to forbid it. Any job where you have to submit a list of prior work with your employment contract (which is most of them in my experience) is usually a sign that there's a clause in there claiming ownership of everything you do while employed there. Personally I doubt it's very enforceable, especially since California is so worker-friendly on everything else I know about, but I don't know how well these clauses work out in practice.