Previous Versions - Restore Folder Behaviour

Hi guys, started using Windows Previous versions to restore some files in my lab. The files are stored on the following:

1. Local
2. Windows Network File Share
3. NetApp Network CIFS share

Restoring files is fine but I'm looking for clarity on the restore folder behaviour. Let me give an example(Note: for the example purpose assume NetApp snapshot and VSS copy are the same thing which essentially they are):

1. Create a folder A
2. Take a snapshot S1
3. Create a file F1 in A and write some data in it
4. Take a snapshot S2
5. Append some more data to F1
6. Take a snapshot S3

Now, if I look at the previous versions for folder A I have 3 restore points. Now:

• If I restore to S1, F1 is still present and has the latest data in in.
• If I instead I restore to S2, F1 now is as it was when I first created it

So, it seems that restoring a folder does the following:

1. Any files that are in the current version of the folder are restored to the version they were at on the restore point selected
2. Any files tat are currently in the folder but are not in the restore point are left alone and remain in the restored folder

Is this understanding correct? Cant find any documentation around this.