 Papers as documents: This typically refers to research papers from journals but increasingly needs to encompass their associated supplementary data . Note also that by far the majority of medicinal chemistry, biological chemistry and pharmacology papers are still behind subscription paywalls. However, the full-text for some of them is not only open but also available to be mined in both PubMed Central (PMC) and European PubMed Central (EPMC) . Connectivity can extend to other document types such as review articles and vendor catalogues. In this article the main document type referred to will be the PubMed Identifier . These have open abstracts and are also indexed in the Digital Object Identifier System (DOI). However, significant numbers of papers in the bioactive chemistry domain (including pre-prints) may be DOI-only.