The damga resmi was originally a charge for the Muhtasib to place an official stamp of purity on gold and silver items (like a hallmark), and for placing an official stamp of authenticity on some manufactured goods, including textiles[2] (also known as damga akmişe).
The charge was usually set at a fortieth of the value of the goods (or 2.5%); sale without the muhtasib's stamp was prohibited, in order to protect revenue.
It could be subject to tax-farming, or iltizam; an individual could buy the "right" to damga resmi fees from the public, in return for paying a lump sum to the state.
[3] Some years after this earlier form of stamp duty had been abolished, the Ottoman treasury invented a replacement; a series of preprinted blank papers with official treasury stamps, which had to be used for almost all official legal and commercial documents (apart from some issued by religious courts).
This is similar to the stamp duty process adopted in some western European countries.