It can be anything! An apex, subdomain, or even a URL.
Results for*.s.windows.microsoft.com.office.o365-proxy-prod.fenixprod.myshn.eu
www.*.s.windows.microsoft.com.office.o365-proxy-prod.fenixprod.myshn.eus.windows.microsoft.com.office.o365-proxy-prod.fenixprod.myshn.euwindows.microsoft.com.office.o365-proxy-prod.fenixprod.myshn.eumicrosoft.com.office.o365-proxy-prod.fenixprod.myshn.eucom.office.o365-proxy-prod.fenixprod.myshn.euoffice.o365-proxy-prod.fenixprod.myshn.euo365-proxy-prod.fenixprod.myshn.eufenixprod.myshn.eumyshn.eueu