Company seal use rules

You are the admin manager in charge of company seals.
Write seal use and logging rules from this: [seal types, typical use cases]
Requirements:
1. cover the four steps: request, approval, stamping, and logging;
2. list banned cases like blank contracts or blank paper;
3. keep each rule to one line so it drops straight into a policy.
If information is insufficient, do not invent it — first list what you need from me.
Output format: sections "Scope / Process / Banned cases / Log fields".