A treasury tag or India tag is an item of stationery used to fasten sheets of paper together or to a folder.
In His Majesty's Stationery Office (HMSO), a treasury tag was a lace with a sharp metal tag at one end which could be threaded through the holes in a stack of documents or cards and then inserted into a female tag at the other end to form a loop, so binding the documents. The tags in that case were in line with the string, like a shoelace. An India tag was similar but the metal tags were orthogonal to the string, so forming a cross-piece. The India tag did not form a loop as the cross-pieces were sufficiently wide that they did not slip back through the holes.
Treasury or India tags are threaded through holes in paper or card made with a hole punch. Strings of various lengths are used to fasten stacks of paper of corresponding thickness and these are sometimes colour-coded by size.
Winston Churchill used treasury tags to hold the notes for his speeches together. He called the punch for making holes a "clop", after the sound that it made. The Duchess of Windsor used India tags for her speeches.