It can be anything! An apex, subdomain, or even a URL.
Results forad.ext.azure.com.office.testdeployment.proxyautomation.myshn.eu
www.ad.ext.azure.com.office.testdeployment.proxyautomation.myshn.euext.azure.com.office.testdeployment.proxyautomation.myshn.euazure.com.office.testdeployment.proxyautomation.myshn.eucom.office.testdeployment.proxyautomation.myshn.euoffice.testdeployment.proxyautomation.myshn.eutestdeployment.proxyautomation.myshn.euproxyautomation.myshn.eumyshn.eueu