| SI | Système International | In French | |
| SIC | Standard Industrial Classification | In English | |
| SII | Standards Institution of Israel | In English | |
| SIM | Sistema Interamericano de Metrología | In Spanish | |
| SIS | Standardiseringen i Sverige | In Swedish | |
| SIST | Slovenian Institute for Standardization | In English | |
| SIST | Slovenski inštitut za standardizacijo | In Slovenian | |
| SLBS | Saint Lucia Bureau of Standards | In English | |
| SLSI | Sri Lanka Standards Institution | In English | |
| SNIMA | Service de Normalisation Industrielle Marocaine | In French | |
| SNV | Schweizerische Normen-Vereinigung (www.snv.ch) | In German | → Organizations and associations |
| SNZ | Standards New Zealand | In English | |
| SOGITS | Senior Officials Group on Information Technology Standardization | In English | → Computer science → Food technology |
| SPAG | Standards Promotion and Application Group | In English | |
| SSPM | Standards and Procedures Manual | In English | → Quality management |
| STRI | Staðlaráð Íslands (www.ist.is) | In Icelandic | |
| SUTN | Slovenský ústav technickej normalizácie | In Slovak | |
| THG | Technical Harmonisation Group | In English | → Engineering, technology |
| TISI | Thai Industrial Standards Institute | In English | |
| TNI | Technické Normalizační Informace | In Czech | |
| TSE | Türk Standardları Enstitüsü | In Turkish | → Organizations and associations |
| TSE | Türk Standardlari Enstýtüsü | In Turkish | |
| TTBS | Trinidad and Tobago Bureau of Standards | In English | → Organizations and associations |
| UME | Ulusal Metroloji Enstitüsü | In Turkish | → Organizations and associations |
| ÚNMZ | Úřadu pro technickou normalizaci, metrologii a státní zkušebnictví | In Czech | |
| USS | United States Standard | In English | |
| VINCI | Valorisation des Innovations, Normalisation - Certification, Conseil, Information | In French | |
| VMT | Valstybinė Metrologijos Tarnyba | In Lithuanian | |
| ZSMP | Zavod za Standardizaciju, Mjeriteljstvo i Patente | In Bosnian | → Industrial property |
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