[libvirt] libvirt domcument question

hi,all when I read the document at http://libvirt.org/formatdomain.html about the domain's xml format ,"disk" element has a optional subelment is "readonly",when I read the paragraph:readonlyIf present, this indicates the device cannot be modified by the guest. For now, this is the default for disks with attribute type='cdrom'. it's say type='cdrom',I'm not sure that is correct or not,I think this is a slips of pen and a possible writting maybe device='cdrom'.forgive me if I misundestanded it. also I'm not sure should send this question to libvirt-list or libvirt-user or others?liuzhijun