What address book Skype for Business is using?

[Petri X]

Hi

I have live in faith that Skype have two address books: Local and web services.

Now that faith has got a sratch: We have done some customization to the contact card based on this:

Customize contact cards in Skype for Business

The surprise hits to me was: depends of where user's mailbox locate it affect to the contact card. I meant when user's mailbox is on-premises the contact cards looks correct. But when user's mailbox is moved to Exchange Online, the contact card did not contains the value.

It looks that if user is using Skype online or Skype on-premises makes no differences.

Based on above, I have a feeling that Skype is using also Outlook's GAL some very strange way. This assumption I have got from elsewhere as well. When you search a person on Skype, and if you are using contact's secondary address (the one which is written with small smtp:) Skype founds that person also.

Is there any clarifications how the Skype is utilizing the address books?

[#2]

If you ctrl+rightclick the skype icon near the clock on the taskbar, there you can check addresslsit search setting and if UCS or Skype is used for addresslist.
If for example Exchange is not hosted in the same environment as Skype for Business, you cant use UCS.
UCS is Exchange way of storing skype contacts.
https://docs.microsoft.com/en-us/skypeforbusiness/deploy/integrate-with-exchange-server/use-the-unif...

[#3]

Yes, I know that, and I have the following information:

Contact List Provider;Skype for Business Server;--;

But as I asked, it looks like the content of the contact card depends of your mailbox location. When the my mailbox is on-premises (does not matter where my Skype is: online or on-premises) I could see those customizations from others. But if my mailbox is migrated to Exchange online (again does not matter where my Skype is) I cannot see those customizations.

So some part on this is heavily depend of the Outlook/Exchange. But who is not able to read that, is unclear for me.