Documentation
Together with the metadata, the documentation provides all the information that ensures the traceability, interpretation, and possible reproduction of the research data or research results. It provides information about what was collected, gathered, or processed by whom, how, with what, why, when, where, and in which context.
The documentation includes the exact description of data generation, processing and indexing as well as the relevant methods and tools (software). This can be in the form of codebooks, (digital) lab books, descriptions of the research design, edition guidelines, or other descriptive documents.
A README file in Markdown or plain text can provide a quick and easy method for data documentation and should be stored together with the data.