It can be anything! An apex, subdomain, or even a URL.
Results forwww.beta.officeapps.live.com.office.zurichairport.myshn.eu
beta.officeapps.live.com.office.zurichairport.myshn.euofficeapps.live.com.office.zurichairport.myshn.eulive.com.office.zurichairport.myshn.eucom.office.zurichairport.myshn.euoffice.zurichairport.myshn.euzurichairport.myshn.eumyshn.eueu