Add an access control entry (ACE) to the access control list (ACL) of a resource access control rule, replace one ACE with another, or remove an ACE from an ACL. The resource rule's ACL is updated by adding, modifying, or removing the ACE, without affecting other ACEs in the list. This is usually simpler and safer than changing the entire list with ALTRESOURCE.
ALTACE combines a DELACE of the old ACE value with an ADDACE of the new one. The old value must exist.