Hi @IC96
To do this for all occurrences in the assembly you can use something like this example ilogic code.
This rule catches errors when the title iproperty is empty, and it also adds an instance number with a colon, so that no errors occur from trying to name multiple occurrences of the same part the same thing.
Note I would make this an external rule and run it on the assembly... and you might set it to run on the 'Before Save' event trigger.
I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com
Dim oAssyDoc As AssemblyDocument
oAssyDoc = ThisApplication.ActiveDocument
Dim oAsmCompDef As AssemblyComponentDefinition
oAsmCompDef = oAssyDoc.ComponentDefinition
Dim oOcc As ComponentOccurrence
i=1
For Each oOcc In oAsmCompDef.Occurrences.AllLeafOccurrences
Try
oOcc.Name = iProperties.Value(oOcc.Name, "Summary", "Title") & ":" & i
Catch
'catch errors ( such as empty title iprop value ) and do nothing
End Try
i=i+1
Next