ID 76 - Reference - What is it used for?

This is a built-in property in M-Files metadata structure that comes by default in all new vaults. The property itself is hidden from the document metadata card so it is not usable in customer configurations and is used only in M-Files internal operations.

As an example: M-Files uses this built-in property with AutoCAD add-in for defining the references from the main image to all the referenced files located in M-Files.

You can find a list of the built-in property definitions in the user guide.