The Council of Europe recommends in R(92)17 that member states consider their own constitutional principles and legal traditions and the independence of the judiciary when taking appropriate measures to eliminate sentencing disparity. An appendix to Recommendation R(92)17 discusses the rationale for sentencing, penalty structures, aggravating and mitigating factors in sentencing, the impact of previous convictions on sentencing, counting time spent in custody toward the sentence, the prosecutor's role in sentencing, and the need for sentencing studies and information sharing. The explanatory memorandum covers general sentencing considerations, the rationale for eliminating sentencing disparity, compatibility between offense seriousness and the sentence, and other issues raised by R(92)17.