data aports;
   keep Start Label Fmtname;
   retain fmtname '$airport';
   set ia.acities (rename = (Code = Start 
                             City = Label));
run;

proc print data=work.aports(obs=10) noobs;
   title 'Airports';
run;

proc format library = ia cntlin = aports;
run;

proc format library = ia fmtlib;
   select $airport;
   title '$airport format';
run;