It can be anything! An apex, subdomain, or even a URL.
www.tao.cn.zb.v4.aserver.tengine.ingress.alibabacorp.comcn.zb.v4.aserver.tengine.ingress.alibabacorp.comzb.v4.aserver.tengine.ingress.alibabacorp.comv4.aserver.tengine.ingress.alibabacorp.comaserver.tengine.ingress.alibabacorp.comtengine.ingress.alibabacorp.comingress.alibabacorp.comalibabacorp.comcom