It can be anything! An apex, subdomain, or even a URL.
Results for*.beta.officeapps.live.com.office.rp-o365.agircarrco.myshn.eu
www.*.beta.officeapps.live.com.office.rp-o365.agircarrco.myshn.eubeta.officeapps.live.com.office.rp-o365.agircarrco.myshn.euofficeapps.live.com.office.rp-o365.agircarrco.myshn.eulive.com.office.rp-o365.agircarrco.myshn.eucom.office.rp-o365.agircarrco.myshn.euoffice.rp-o365.agircarrco.myshn.eurp-o365.agircarrco.myshn.euagircarrco.myshn.eumyshn.eueu