It can be anything! An apex, subdomain, or even a URL.
Results for*.login.live.com.office.o365rp.fcc.myshn.eu
www.*.login.live.com.office.o365rp.fcc.myshn.eulogin.live.com.office.o365rp.fcc.myshn.eulive.com.office.o365rp.fcc.myshn.eucom.office.o365rp.fcc.myshn.euoffice.o365rp.fcc.myshn.euo365rp.fcc.myshn.eufcc.myshn.eumyshn.eueu