★What is the difference between attachment and overlay of reference type

Issue:

When drafting in ZWCAD, it is often necessary to attach other drawings as references. In such cases, when attaching an external reference, there are two reference types available: Attachment and Overlay, as shown in the figure below. What is the difference between the Attachment and the Overlay?

Solution:

The only difference between attachment and overlay types is how they handle nested references. When attaching a drawing with an external reference to another new drawing, these two types behave completely differently.

Attachment type: The reference drawing will be passed all the way. For example, when attaching A to B,  then attaching B to C, then B and A will be seen in C at the same time.

Overlay type: The reference drawing will not be passed. For example, when overlaying A to B, then attaching B to C, then only B can be seen in C, not A.

★What is the difference between attachment and overlay of reference type：https://confluence.zwcad.com/pages/viewpage.action?pageId=315655574