classes/slots meaning?

[Ballet]

there is a column called "classes"
but that is a numbers.

i know 32767 = all classes.
there's some algorithm to convert it to all, war only, caster only, bla bla bla.
but i dont know how.

so as slots.
anyone got a good algorithm willing to share?

I am writing a program to read the item db (dumpeditems.sql) and calculate the "points" based on formula for my guild looting system.

so understanding that kind of numbers meaning would help me a lot.

Thank you very much