Michael's Ecclectic list of IoT related IETF Working Groups

In alphabetical order:

ACE: Authentication and Authorization for Constrained Environments WG (SEC)
ANIMA: Autonomic Networking Integrated Model and Approach WG (OPS)
ASDF: A Semantic Definition Format for Data and Interactions of Things WG (ART)
CBOR: Concise Binary Object Representation Maintenance and Extensions WG (ART)
CORE: Constrained RESTful Environments WG (ART)
COSE: CBOR Object Signing and Encryption WG (SEC)
DANISH: DANE AutheNtication for Iot Service Hardening BOF
DNSSD: Extensions for Scalable DNS Service Discovery WG
DRIP: Drone Remote ID Protocol WG (INT)
HOMENET: Home Networking WG (OPS)
IOTOPS: IoT Operations WG (OPS)
LAKE: Lightweight Authenticated Key Exchange WG (SEC)
LPWAN: IPv6 over Low Power Wide-Area Networks WG (INT)
RATS: Remote ATtestation ProcedureS WG (SEC)
ROLL: Routing Over Low power and Lossy networks WG
T2TRG: Thing-to-Thing Research Group (IRTF)
TEEP: Trusted Execution Environment Provisioning WG (SEC)
SUIT: Software Updates for Internet of Things WG

Some other Working Groups that seldom deal with IoT, but should