[en] The computer program COGEND is described. It is used to generate nuclear decay scheme data in standard ENDF/B-IV or V format as required by the user. Output consists of a printed summary of the input data, a listing of the resulting ENDF/B format data and the ENDF/B data produced in the required medium - punched cards, magnetic tape or magnetic disk. COGEND includes routines to calculate, from input spectral data, values of:- mean alpha and gamma energies; mean beta energies, allowed to 4th unique forbidden transitions by means of an 'exact' method; conversion electron energies and intensities; K-, L-and shell capture ratios in electron capture decay; K-, L- and M- shell Auger electron energies and intensities; K-, L- and M- shell X-ray energies and intensities; energy of the recoil nucleus in alpha decay; and internal bremsstrahlung emission associated with beta decay. In addition, COGEN automatically summarises details of the decay scheme, in an easily readable form, in the comments section of the ENDF/B output. The mathematical methods employed and the data sources used are described in detail in this report. Full input specifications are provided and a test case is illustrated in order to assist the user in running COGEND. (author)