This ReadMe document provides a description of the spreadsheet providing details on the data sources, assumptions, formulae, and computations used to derive catch limits in accordance with IOTC Resolutions 19/01, and 21/01. The spreadsheet is intended to ensure transparency and facilitate the review and verification of the calculations and resulting catch limits. Although Resolution 18/01 remains applicable to India, it does not include a catch limit and is therefore not covered in the spreadsheet.