[CF-metadata] Dimensionless Vertical Coordinates

[John Caron]

In the CF-1 Metadata Conventions, Appendix C at

   http://www.cgd.ucar.edu/cms/eaton/netcdf/CF-20010808.htm

Dimensionless Vertical Coordinates standard names are listed as:
   sigma
   hybrid_sigma_pressure
   hybrid_height

But in the "standard name table" at

   http://www.cgd.ucar.edu/cms/eaton/netcdf/standard_name_20010915.html

these names are listed:

  atmosphere_sigma_coordinate
  atmosphere_hybrid_sigma_pressure_coordinate
  atmosphere_hybrid_height_coordinate
  ocean_sigma_coordinate:
  ocean_s_coordinate

with no further explanation of what they are except for "see appendix".

which is normative, and if the latter, where are these defined?