Suppose you have to place a part several times in an assembly and yet you want a unique code, name or number attached to each occurres of that part. This can be accomplished by making a copy of that part for each inserted part, providing it with a custom property and then save the unique code in there. After that, you can insert all these copies into the assembly file.

For large assemblies or if the part has a large file size, this is not a good solution. If the parts must be adaptable simultaneously, this workflow is not possible, and each part will have to be adapted individually. 

I built this application to be able to give parts with the same definition document, a unique code, name or number inside an assembly.

Note that this TAG only exists in the assembly file and is connected to an occurrence of the part.

The original part document will not be modified and the connection to all occurrences in the assembly stays intact. If the occurrence of a part in an assembly is deleted the TAG number is also deleted.

If the assembly is inserted into a drawing file, there are also three commands available to manipulate the TAG numbers in a drawing file.

Note: This app uses a custom installer (and not the standard App Store installer).