Hi Vincent,
Two licenses are provided: one license from Autodesk for AS and one license from GRAITEC for Advance CAD.
The GRAITEC Advance CAD license allows running Advance CAD without Autodesk Advance Steel.
These 2 licenses are not linked and can be theoretically split on 2 computers but in this case the user should supply an AutoCAD license or another Advance CAD license for allowing Autodesk Advance Steel to run.
If you are running AS 2015 with AutoCAD 2015 the Hotfix does not apply too you only to those users who do not have AutoCAD and are using Advance CAD along with AS 2015 on standalone. See attached zip file.
Attachment: Service pack HotFix2.zip