It can be anything! An apex, subdomain, or even a URL.
Results forwww.sharepoint.microsoftonline.com.office.o365rp.fcc.myshn.eu
sharepoint.microsoftonline.com.office.o365rp.fcc.myshn.eumicrosoftonline.com.office.o365rp.fcc.myshn.eucom.office.o365rp.fcc.myshn.euoffice.o365rp.fcc.myshn.euo365rp.fcc.myshn.eufcc.myshn.eumyshn.eueu