The dataset package extension to the R statistical environment aims to ensure that the most important R object that contains a dataset, i.e. a data.frame or an inherited tibble, tsibble or data.table contains important metadata for the reuse and validation of the dataset contents. The aim of dataset is to produce to turn R data frames into datasets that meet strict application criteria, can participate in the Statistical Data and Metadata eXchange, or send data to Wikidata, Europeana, and various open science repositories. The current version of the dataset package is matureing. It was peer-reviewed and became part of rOpenSci. at version 0.4.0. The 0.4.1 version works better with data and time classes, and allows flatting the semantic informatin of the rich datasets to place them back to base R or tidyverse pipelines.