0x00" = None "0x01" = Hyper-V "0x02" = VMware "0x04" = Virtual PC "0x08" = Xen PC
But CQD for non virtual Windows machines offers the value 0x01 > 80% of cases and 0x00 the rest . For VDI installations in general the value is *. We are using Citrix and never we've seen 0x08. Somebody knows if this is a kind of bug or we are wrong in something?
The First / Second Virtualization Flag field is a Skype for Business column, Microsoft Teams clients do not accurately populate this field. We've released new fields specifically for Teams VDI scenarios (search 'VDI' in the document page you linked).
I've submitted an update for the documentation to point out that this field applies to Skype for Business endpoints only, and that VDI in Teams is handled by different dimensions in CQD.