Store list inside 3DM file

Hi, Is it possible to store a list of objects inside the file via IronPython?

I could use this hidden list for pre-selection that could be beneficial in certain cases not to loop through all of the objects in the file just only those in the list.

You could use custom user document data: https://github.com/mcneel/rhino-developer-samples/tree/6/rhinocommon/cs/SampleCsUserData