ACLid

ACLid is a term used to denote the unique identifier assigned to an entry within an access control list (ACL). It functions as a stable handle that distinguishes individual permission entries in an ACL, facilitating management, auditing, and policy evaluation. There is no universal specification for ACLid; implementations typically choose a numeric sequence, a UUID/GUID, or a short alphanumeric string. The format chosen can affect persistence, scoping, and how ACL revisions are tracked.

In practice, an ACLid is created when an ACL entry is added and is retained across updates to the ACL. It may be used by policy engines and authorization services to reference specific entitlements without parsing the entire ACL. ACLids enable operations such as entry modification, deletion, or conditional inheritance by referring to the entry via its identifier rather than rewriting its description.

Across different domains, ACLid usage varies. In file systems, ACLids might be stored alongside permission bits and inheritance flags. In databases and cloud identity and access management (IAM) systems, they enable efficient auditing, partial updates, and cross-referencing with external policy catalogs. Some systems expose APIs to enumerate ACLids, fetch associated metadata (such as principals, privileges, and inheritance), and audit history. Security practices emphasize protecting ACLids, restricting changes to authorized administrators, and logging changes for accountability.

See also: Access control list, Identity and access management, Policy management, Audit trails.