RC_TYPENAMES = c("tail correlation function", "positive definite",
    "variogram", "negative definite", "process", 
    "method for Gauss process", "method for Brown-Resnick process",
    "shifted shape function",
    "distribution family", "shape function", "trend", "interface",
    "undefined", "other type")  RC_DOMAIN_NAMES = c("single variable", "kernel", "framework dependent", "mismatch")
  RC_ISONAMES = c("isotropic", "space-isotropic", "zero-space-isotropic",
    "vector-isotropic", "symmetric", "cartesian system",
    "earth system", "spherical system", "cylinder system",
    "non-dimension-reducing", "parameter dependent",
    "")
  RC_MONOTONE_NAMES = c("mismatch in monotonicity",
                 "submodel dependent monotonicity",
                "previous model dependent monotonicity",
                "parameter dependent monotonicity",
                "not monotone", "monotone", "Gneiting-Schaback class", 
                "normal mixture", "completely monotone", "Bernstein")
 
  RC_ISOTROPIC gives the numerical code for option
  "isotropic"
  
  RC_SPACEISOTROPIC gives the numerical code for option
  "space-isotropic"
  RC_CARTESIAN_COORD gives the numerical code for option
  "cartesian system"
  RC_GNOMONIC_PROJ gives the numerical code for
  the gnomonic projection, see also zenit in RFoptions.
  RC_ORTHOGRAPHIC_PROJ gives the numerical code for
  the  orthographic
  projection, see also zenit in RFoptions.
  RC_EARTH_COORDS gives the numerical code for option
  "earth coordinates"
  RC_SPHERICAL_COORDS gives the numerical code for option
  "earth coordinates"
  RC_OPTIMISER_NAMES and RC_NLOPTR_NAMES give the
  names for the options optimiser and algorithm,
  respectively, RFfitoptimiser.
  RC_LIKELIHOOD_NAMES = c("auto", "full", "composite",
    "tesselation")
  gives the names of the ML variants: (i) internal
  choice according to the
  number of data, (ii) full likelihood, (iii) (pairwise) composite likelihood,
  and (iv) composite likelihood based on a tesselation of the space.