Most editors use 'reg' now for all data. Use is discouraged. Can replace 'rd' as a single field for all data. When possible include name of registrant, date of registration, and cite published registration using an 'li' field. Use the taxonomic Section name only.
Field is largely unused to date.
Use official taxonomic names. If possible include density per unit of stem, color, size, etc. if atypical. If the file is in HTML format please use a full A HREF clickable citation. If using an MPI-related link use the 'mpi' field instead. We have always maintained that the NOD fields should be kept as flexible and free-form as possible to accomodate the needs of authors and users.