Consistency in variable names
I would propose to keep the names of common input and output arguments like M_, options_, oo_, estim_params_, bayestopt_, dataset_, dataset_info, estimation_info consistent throughout the code base. For instance in dsge_likelihood.m, dsge_var_likelihood.m, non_linear_dsge_likelihood or in the functions of the identification toolbox we use names like DynareOptions, or options (without underscore). So maybe, right before we release 4.7, we could make the names consistent? This would be a simple text search and replace, but everyone would then need to rebase local branches to this.
I think these are the most important variables (feel free to add to this list):
M_options_oo_estim_params_bayestopt_dataset_dataset_infoestimation_info