_parc()            Retrieve a character parameter
 _parclen()         Retrieve the length of a character parameter
 _parcsiz()         Retrieve the memory allocated for character parameters
 _pards()           Retrieve a date parameter as a string
 _parinfa()         Determine length or element type of an array parameter
 _parinfo()         Determine the parameter count or data type of a parameter
 _parl()            Retrieve a logical parameter as an int
 _parnd()           Retrieve a numeric parameter as a double
 _parni()           Retrieve a numeric parameter as an integer
 _parnl()           Retrieve a numeric parameter as a long
 _ret()             Post a NIL return value
 _retc()            Post character return value using null-terminated string
 _retclen()         Post a character return value with explicit length
 _retds()           Post a date return value using a date string
 _retl()            Post a logical return value
 _retnd()           Post a numeric return value using a double
 _retni()           Post a numeric return value using an integer
 _retnl()           Post a numeric return value using a long
 _storc()           Assign a null-terminated string to a referenced variable
 _storclen()        Assign string of explicit length to a referenced variable
 _stords()          Assign a date string to a referenced variable
 _storl()           Assign a logical value to a referenced variable
 _stornd()          Assign a numeric to a variable using double-precision type
 _storni()          Assign a numeric to a referenced variable using an integer
 _stornl()          Assign a numeric to a referenced variable using a long