If no Format value is set for a Frame axis, a default value is supplied instead. This is based on the value of the Digits, or Digits(axis) attribute and is chosen so that it displays the requested number of digits of precision.
The interpretation of this string depends on whether or not the Frame is a SkyFrame. If it is not, the string is interpreted as a format-specification string to be passed to the C ``printf'' function (e.g. "%1.7G") in order to format a single co-ordinate value (supplied as a double-precision number).
For SkyFrames, the syntax and default value of the Format string is re-defined to allow the formatting of sexagesimal values as appropriate for the particular celestial co-ordinate system being represented. The syntax of SkyFrame Format strings is described (below) in the ``SkyFrame Formats'' section.
KAPPA --- Kernel Application Package