well if that info you provided (three lines) is a header, it's most likely ALL tabs, you just said it's a header. A header by nature can only be one line, unless items wrap within each element.
array_diff() might help...
$a1=array("Cat", "Dog", "Snake");
$a2=array("Snake", "Dog", "Rabbit");
count($a1) = 1
$a1 = Cat
Any array element in $a1 that matches an element in $a2 will be removed, reducing the array to only non-matches.
Please explain 'field checks'.