This task upgrades an old-style RGS combined event list for minimal compliance with current specifications for the filtered, combined event list. Minimal compliance means that it meets the requirements of rgsregions, rgsspectrum and rgsrmfgen. The conversion is performed in-place and the input file is destructively changed in the sense that any obsolete constructs are converted and removed. If the input file possesses none of these constructs it is left unchanged. Consequently, this task may be invoked repeatedly on the same file, or on a combined event list that already meets current specifications, without concern for damage or error.