I am looking for some docs/sap note regarding the SQL Server 2012 DB runtime license limitations, but I do not find any.
I was able to find only the license scope note which says that it can not be used for other applications, which is quite obvious in fact.
I could find from Microsoft, Juergen Thomas' blog:
From SAP side, SAP only will distribute the Enterprise Edition which is licensed per core and hence unlimited within the frame of their ISV-R/Reseller contract with Microsoft.
Could you please share any info/note which officially states this?