It can be anything! An apex, subdomain, or even a URL.
Results forwww.teams.microsoft.com.4test12.o365---bdl.btfrancedemo.myshn.net
teams.microsoft.com.4test12.o365---bdl.btfrancedemo.myshn.netmicrosoft.com.4test12.o365---bdl.btfrancedemo.myshn.netcom.4test12.o365---bdl.btfrancedemo.myshn.net4test12.o365---bdl.btfrancedemo.myshn.neto365---bdl.btfrancedemo.myshn.netbtfrancedemo.myshn.netmyshn.netnet