Maybe try using an advanced rule with this template
Code:
program:
fmts = field('formats');
common = 'epub, pdf, azw3, mobi, cbz, paperbook';
diff = list_difference(fmts, common, ', ');
cnt = count(diff, ',');
test(cmp(cnt,0,'','','gt'),'question-mark.png','')
replace 'question-mark.png' with the name of your icon. Also note that the multiple assignments here make the template slower, but more readable.