English language Single Document Interface Strategic Defense Initiative Serial Digital Interface Less common expansions include: Saratoga Direct Inc. Sarawak Development Institute Scientific Development and Integration Scion Digital Imaging Scuba Diving International Selective Dissemination of Information Serial Data Interface Serial Digital Interface (Broadcast video standard) Service Dimensions Inc. Seoul Development Institute Socratic Dialogue Inducing Lab Software Dynamics, Incorporated Southern Dental Industries Limited Spatial Development Initiatives Space Science and Engineering Center (SSEC) Desktop Ingestor Spatial Data Infrastructure Spatial Data Integrations, Inc. Stamp Dealers International State Disability Insurance Statistics on Depository Institutions Steel Deck Institute Steel Dynamics Inc. Strategic Diagnostics Inc. Strategic Directions International Strategic Distribution, Inc. Strengthening Democratic Institutions Project Sustainable Development Indicators Sustainable Development Information Sustainable Development Initiative Systems by Design of Illinois Systems Documentation, Inc. Other languages Szybki Dostep do Internetu, later renamed to Staly Dostep do Internetu Schaumburg Dienstleistung für Informationstechnik Soluzioni d'Impresa Socialisti Democratici Italiani System-dynamische Interventionen