if you have just 1 or 2 suitcases, you don't have to fill out a b4.  if you are bringing an entire wardrobe and all of your worldly possessions, then you have to fill out the form.  no, you don't have to be specific.  if you have 2 boxes of books, you write "2 boxes of books" and assign a value.  if you have a bag/box of jewelry, you put "box of jewelry" and assign a value,  if you are bringing furniture, you describe the furniture and assign a value,  if you are bringing computers or tvs, you want to list them separately.  you don't have to declare a cell phone or jewlery  or clothing you are wearing.  you only declare items that are beyond everyday stuff you are traveling with.