Reserve Bank on Thursday asked the public not to write on the watermark window of banknotes as it bears an important security feature which differentiates it from a fake note.
RBI said it was brought to its notice that members of public and institutions write number, name or messages on the watermark window of banknotes and thus deface the currency.
"The watermark window has an important security feature which distinguishes it from a counterfeit note. Any defacement on the window will not allow the common man to identify one of the features of a genuine note," RBI said in a notification.
"The public is, therefore, requested to refrain from doing anything that leads to defacement," it added.