UnderSide ( Classic ) : The underside version is generally a common bookmark style which can be named as a classic style. If you read a novel for instance and put it on a table temporarily, you generally use the classical bookmark version. However, not all the books have this genre like novels. That is why we created another version which is upside one.
Upside ( For the Bookshelf ) : We created an upside version for the books that can have reference resources like a dictionary. These kinds of books are read all the time and they are not finished but rather they have encyclopedic references and you read them from time to time and shelve them. For many students and researchers while they are focusing on a subject, they read these kinds of books regularly.