The Pharma Documentation Ring (P-D-R), founded in 1958, is a think tank of information and knowledge-management professionals representing major research-based pharmaceutical companies. The association has four aims: One of P-D-R's initial aims was to select and index relevant documents from the scientific literature, to write abstracts and index them based on agreed rules, and to distribute copies of the corresponding punched cards and microfilms to all cooperating members. Due to the limited space on a punched card, the P-D-R-affiliated companies developed fragment codes for chemical structures and biomedical terms allowing them to index all relevant aspects of the publications properly. The Ringcode was born and survived for several decades, even replacing more sophisticated techniques. More information...
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