What are SIGN Guidelines? SIGN ( Scottish Intercollegiate Guidelines Network) These publications are based on the best or strongest evidenced medical research available at the time of publication. They are used as the base for best clinical practice in hospital and community.Although published in Scotland the evidence is gathered from stroke research across the world. The guidelines are reviewed and updated when necessary.  Sections are recorded from A to D with A being the most strong researched evidence for a treatment. If there is insufficient published research on a topic, a good practice recommendation can be made.