This lecture will explain how to enable AutoCAD software associative dimensions on complex custom AutoCAD entities using regular AutoCAD dimension and annotation commands. It will provide a complete and realistic code example that can be copied and tailored to individual needs. The main concept explained in this lecture will be the concept of a Persistent Subentity Id Protocol Extension. Custom AutoCAD entities need to implement and expose this protocol extension to reveal their subentities and to define their Persistent Subentity Ids. The AutoCAD associative dimensioning and annotation mechanism then interacts with the custom entities via this protocol extension. This session features AutoCAD. AIA Approved