It can be anything! An apex, subdomain, or even a URL.
Results formsg.skype.com.office.o365.phoenixprod.myshn.eu
www.msg.skype.com.office.o365.phoenixprod.myshn.euskype.com.office.o365.phoenixprod.myshn.eucom.office.o365.phoenixprod.myshn.euoffice.o365.phoenixprod.myshn.euo365.phoenixprod.myshn.euphoenixprod.myshn.eumyshn.eueu