PPSs intend to facilitate communication, as pictures represent better than words certain information, such as relative size and connection of pieces. R Relevance Importance or significance. Differential feature of a subset of information that makes it of interest for the receiver. Relevance is a key concept, because it depends on the subject receiving the information. What is relevant for one person can be useless for another and hence can be disinformation or even 'rubbish'.
Relevance is especially important when speaking about information retrieval.
Repetitive structure Structure of procedures that includes steps which may be performed more than once by the reader. S Sign Something that evokes in the mind the idea of something else by its very nature or by convention . Examples of signs are the letters that we write or the components of the musical notation. Sometimes the signs are part of the symbols. The study of signs is called semiotics.