jQuery.uniqueSort()

Sorts an array of DOM elements, in place, with the duplicates removed. Note that this only works on arrays of DOM elements, not strings or numbers.

.data()

Store arbitrary data associated with the matched elements or return the value at the named data store for the first element in the set of matched elements.

jQuery.grep()

Finds the elements of an array which satisfy a filter function. The original array is not affected.