!s% means that the output is to be displayed as a string of characters, not a number which can be operated upon. The "ident" in aviation means the audible morse signal. Pilots don't use the written letters, although they are printed on charts so that they know what to listen out for when switching the VOR receiver or audio channel switcher to "Ident". Approaching Wallasey? Listen out for dih-dah-dah di-dah di-dah-di-dit. Inceidentally, bones, I once tried to write a means of remembering morse letters, one of example of which was "The 'ELL it is" (a la John Wayne) which has the rhythm, when spoken, of the morse letter L and "Charlie Charlie" which has the rhythm of morse C. Was there ever such a system in fact? Peter