Documents are tools of communication which are changing rapidly in nature and quantity. Prompted by the COVID-19 pandemic, digital formats have become ubiquitous. However, documents and documentation have a long pre-digital history. In seeking to survey document types and features, two major online journal databases from the Web of Science database were analysed over a 30-year period to 2020. Documents were classified into types and the (arbitrary) features of format, dimension, production, administration and distribution. Such tabulation of journal documents has not been undertaken previously. As the sampled journals covered a range of fields, the types and features of documentation in selected specialised areas were included. Digitalisation of documentation, especially of rare documents, has accelerated in recent times, contributing to the retention of knowledge and its rapid dissemination, despite the accompanying disadvantages of the digital age, with its largely unregulated social media. Classifying and describing the diversity of existing documents is a major task and we have initiated this process by analysing two scientific databases.