Not everyone gets it. It is generated by the computer (AFAIK) and is based on the answers you gave in the application or a discrepancy found by the computer. Many a times the IOs do not even look into it, but it is best to take whatever documents are requested. Asking for state ID implies ... but is not always 100% ... some issues with address. Either you moved recently, or you live in one place but work in another or carry license from another place ... or as I said, it could be random computer bug.