We have an ambiguous benchmark tag that has 23 questions but no usage guidance and seems to be being used for several quite different things.
Refers to a forecasting model which is used as a standard by which a more complected model (i.e VARs and VECM) must out preform. Usually the historical mean, median or some form of an ARIMA class of model is used as a the model which the more complected one must outperform to display the model's effectiveness in comparison.
But there seem to be rather more questions about benchmarking code runtimes etc eg here.
I have a feeling that the tag should be split into two cases and "benchmark" itself dropped for being potentially ambiguous. But I'm not an expert on either of these two areas.
There are a few threads that do not seem to fit within either of these categories, eg here (which might be better regarded as a request for a canonical exemplar data set) and here (where "benchmark" seems to be referring to educational standards), but these usages seem too rare to require disambiguating and perhaps the tag should simply be removed.