evidence: The Reserve Bank of India (RBI) on Friday revised the existing guidelines for authentication and sorting the new series of banknotes and issued guidelines directing banks to test their banknote sorting machines on a quarterly basis. [...] The unfit Bank Notes like soiled notes, limpness, dog-ears, notes with tears, holes, stains, Graffiti, crumples/folds, decoluration, repair, mutilated, imperfect, mismatched notes and built-up notes have been phased out by the Reserve Bank of India from time to time. As per the direction of the RBI, the sorting machines used by banks shall sort all the phased-out notes as unfit, irrespective of their physical condition. [...] According to the RBI guidelines, soiling refers to the general distribution of dirt across the entire note or in some patterns. It is a measure of the loss of reflectivity from the unprinted areas due to dirt, ageing (yellowing), wear and extraneous markings and includes decolouration due to ageing, excessive folding and other wearing. While evaluating for soiling, both the obverse and the reverse of the note shall be checked and notes exceeding the soiling level specified by RBI shall be sorted out as unfit.