Exchange Server shared mbx licensing (with archiving)

Hi there,

we have a customer who uses the online archive for his on-premises mailboxes. Licensing here is clear.
But now he wants to activate the in-place archive (on-premises) for some special mailboxes.

So I researched about the licensing for this. Unfortunately I did not find inforamtion dedicated to shared mbx. But in general information are about the premium feature itself and there it is written, that the in-place archive needs an Enterprise CAL. But that was already clear so far. 

In general an Enterprise CAL is an add-on for a Standard CAL, so you need both.

If I create a shared mailbox with an archive and check this with Get-ExchangeServerAccessLicenseUser -LicenseName "Exchange Server 2016 Enterprise CAL" I can find the new shared mbx.
But if I now check for Get-ExchangeServerAccessLicenseUser -LicenseName "Exchange Server 2016 Standard CAL" I will find the shared mbx as well.

Will I need a Standard and an Enterprise CAL for a shared mailbox with In-Place archive activated?

Thanks in advance.

Kind regards,

woelki