Host file contains 200 instances of TAG1 . Someone edits TagBlock.dwg and changes the attribute tag to TAG1_NEW . The host file now shows #### for every instance. ATTSYNC won’t recover lost data—it just deletes old values. The only safe upgrade is a custom LISP that maps old tag values to new tag names before syncing.

Your future self will thank you every time you hit I (Insert) and find exactly what you need in seconds.

Why Distinguish Host Files from Block Source Files?

However, the concept remains identical. Even in Autodesk Vault or BIM 360, you are still defining a for your blocks. The keyword "full" now implies you have populated your Cloud Content library with all necessary families (Revit) or blocks (AutoCAD).