Here’s a concise review of the concept and practical application of an (more accurately called a legal requirements register or compliance obligations register ).
While the standard doesn't strictly use the term "legal register," it mandates that organizations their compliance obligations.
If you don't have a column for "Status," you are unable to demonstrate the performance evaluation required by Clause 9.
If you cannot produce of compliance for a listed requirement, that becomes a nonconformity (major if systemic or risk-significant).
If there is one section of an ISO 14001 audit that causes the most anxiety for Environmental Managers and Quality Directors, it is usually Clause 6.1.3: Compliance Obligations.