All parts of a call number must be taken into account if you are to find the item on the shelf. Then there will be some numbers or letters to identify the particular item. In this example 333.78216 is the DDC Number and CRES identifies the particular item. Note that in the UTS Library there are two systems of Call Numbers. Newer items end in letters.
Older items end in numbers.
I tems using letters in the call number are filed after items using only numbers.