%% You should probably cite rfc9465 instead of this I-D.
@techreport{ietf-pim-null-register-packing-10,
    number =    {draft-ietf-pim-null-register-packing-10},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-pim-null-register-packing/10/},
    author =    {Vikas Ramesh Kamath and Ramakrishnan Cokkanathapuram Sundaram and Raunak Banthia and Ananya Gopal},
    title =     {{PIM Null-Register packing}},
    pagetotal = 10,
    year =      2021,
    month =     sep,
    day =       12,
    abstract =  {In PIM-SM networks PIM Null-Register messages are sent by the Designated Router (DR) to the Rendezvous Point (RP) to signal the presence of Multicast sources in the network. There are periodic PIM Null-Registers sent from the DR to the RP to keep the state alive at the RP as long as the source is active. The PIM Null-Register message carries information about a single Multicast source and group. This document defines a standard to send multiple multicast source and group information in a single PIM Null-Register message, in a packed format. We will refer to this packed format as the PIM Packed Null-Register format throughout the document. This document also discusses the interoperability between the PIM routers which do not understand the packed message format with multiple multicast source and group details.},
}