Client records cannot be archived (soft delete); they are permanently deleted when removed Client post meta is limited to 1000 characters per value (WordPress limitation) Email is stored in post meta, not as a separate indexed field (consider custom database implementation for large datasets) Client-to-user assignment is one-to-one; a client can only be assigned to one user Deleting a user does NOT automatically unassign clients; manual cleanup may be needed Client detail page extensibility relies on plugin initialization timing; some plugins may need higher hook priority