I am reviewing draft-ietf-bier-isis-extensions-07 on behalf of the ops directorate in an effort to ensure attention to operational considerations. This document defines a new sub-TLV for IS-IS for use with BIER. It also defines an IANA registry for additional sub-sub-TLVs for this new BIER sub-TLV. Overall, this document is ready with some nits. The only substantive comment I have is in section 5.6 regarding reporting misconfigurations. What is not stated is _how_ this is to be done. There is no reference to a standard BIER or IS-IS mechanism with how this reporting should be carried out. For operational consistency, I feel some guidance should be offered. The one nit I noticed is in section 6.2: OLD: Label ranges in multiple sub-sub-TLV MUST NOT overlap. NEW: Label ranges in multiple sub-sub-TLVs MUST NOT overlap.