It would be nice to emit warnings whereever the compatibility functions are invoked, so that we don't forget to convert them eventually. {subsubsection: Invisible Attributes} -Old {quote:ClassAds} support the notion of private attributes that can be marked invisible when exporting an ad. The set of invisible attributes is static and invisibility is only done for the put() and dPrint() calls, so we handle this strictly in the compatibility functions. +Old {quote:ClassAds} support the notion of private attributes that can be marked invisible when exporting an ad. The set of invisible attributes is static and invisibility is only done for the put() and dPrint() calls, so we can handle this strictly in the compatibility functions. {subsubsection: String Escaping} String escaping is different between new and old {quote:ClassAds}.