[en] This document summarizes the contents and documentation of the new version of tile Russian Reactor Dosimetry File (RRDF-98) released in December 1998 by the Russian Center on Nuclear Data (CJD) at the Institute of Physics and Power Engineering, Russian Federation. This file contains the original evaluations of cross section data and covariance matrixes for 22 reactions which are used for neutron flux dosimetry by foil activation. The majority of the evaluations included in previous versions of the Russian Reactor Dosimetry Files (BOSPOR-80, RRGF-94 and RRDF-96) have been superseded by new evaluations. The evaluated cross sections of RRDF-98 averaged over 252-Cf and 235-U fission spectra are compared with relevant integral data. The data file is available from the IAEA Nuclear Data Section on diskette, cost free. (author)