item wise stock required ? can we maintain stock category wise for self use

there is no specific mention about this in rules or act....rules lays down some particulars to be maintain regarding stock like os, cs, received, sold, transferred etc. these rules should be followed. if by maintaining category wise record if the goods are identifiable readily, than I think it is good to go. I mean if maintaining category wise dealer made it impossible or cumbersome to tally the stock than it is advisable to make item wise stock, otherwise category wise may be maintained. In some cases it is really impossible to make item wise records, specifically for small dealers, like nut bolts, than there is no choice but to make category wise details.