Support to agriculture producers is provided in different forms, including border measures, domestic subsidies, and income transfers from taxpayers to producers. International Food Policy Research Institute (IFPRI) maintains a harmonized database on nominal rate of protection (NRP) for the AgIncentives Consortium (www.ag-incentives.org) constituted by OECD (Organization for Economic Co-operation and Development), FAO, IFPRI, the Inter-American Development Bank (IADB), and the World Bank. The database provides measures of the extent of market price distortion of agricultural products caused by border measures, such as tariffs, quotas, trade bans, export taxes, etc. While the NRP has been the focus of this database to date, the Ag-Incentives Consortium has decided recently to also include estimates of the nominal rate of assistance (NRA) in the database. The NRA includes subsidies and income transfers in addition to price support through border measures, thus providing a more complete picture of the extent of producer support to the agricultural sector. This document describes the different steps of data processing, mapping of payment types to NRA categories, nomenclatures followed etc. Starting with an overall methodology, the document presents data processing steps and procedures followed for each source of data received from IOs.