Revit is not just a modelling tool it is a vast database of information, and every piece of modeled information can be identified uniquely by its ID number.
To be able to identify every element by its individual ID number is extremely useful when you run into error messages like this……..
Or when you run a warning report on your model and you need to try clear out the warnings, usually the only way to determine what the warning is related to is through its ID number.
If you need to find in your model elements only identified by their ID number, then if you go to the Manage Ribbon, and select the ‘Select by ID’ tool.
All you need to do now is to type in the ID number (or numbers, use a semicolon between) and Revit will scan the model and select the elements.