The SNOMED CT URI standard defines a standard format of URIs for identifying various SNOMED CT artefacts including components and RF2-based releases. As a specific sub-case this includes URIs for formally identifying the SNOMED CT international edition, extension editions, and any specific versions thereof.

Status

The SNOMED CT URI standard version 1.0 has been published at http://snomed.org/uri. 

Future Versions

Additional requirements have been collected for inclusion in a future version 1.1 of the SNOMED CT URI standard. The proposed additions are described below.

URIs for Language Syntaxes

Examples of language syntax URIs:

• SCG - SNOMED Compositional Grammar (with version option)
  • http://snomed.info/syntax/scg
  • http://snomed.info/syntax/scg/version/2.1
• ECL - Expression Constraint Language (with version option)
  • http://snomed.info/syntax/ecl
  • http://snomed.info/syntax/ecl/version/1.2
• QRL - SNOMED Query Language (with version option)
  • http://snomed.info/syntax/qrl
  • http://snomed.info/syntax/qrl/version/1.0
• STS - SNOMED Template Syntax (with version option)
  • http://snomed.info/syntax/sts
  • http://snomed.info/syntax/sts/version/1.0
• ETL - Expression Template Language (with version option)
  • http://snomed.info/syntax/etl
  • http://snomed.info/syntax/etl/version/1.0
• CTL - Expression Constraint Template Language (with version option)
  • http://snomed.info/syntax/ctl
  • http://snomed.info/syntax/ctl/version/1.0
• QTL - Query Template Language (with version option)
  • http://snomed.info/syntax/qtl
  • http://snomed.info/syntax/qtl/version/1.0

URIs for Language Syntax Instances

Examples of language syntax instance URIs:

• ID - Concept
  
  • The concept "404684003 |Clinical finding|"
    • http://snomed.info/id/404684003
  • The concept "404684003 |Clinical finding| in the 20160731 international release
    • http://snomed.info/id/900000000000207008/version/20160731/id/404684003
      
• SCG - Expression
  
  • The expression "404684003 |Clinical finding|: 47429007 |Associated with| = 79654002|Edema|"
    • http://snomed.info/scg/404684003%3A47429007%3D79654002
  • The expression "404684003 |Clinical finding|: 47429007 |Associated with| = 79654002|Edema|" based on the 20160731 international release
    • http://snomed.info/sct/900000000000207008/version/20160731/scg/%3C404684003%3A%3C%3C47429007%3D%3C%3C79654002
  • The expression "404684003 |Clinical finding|: 47429007 |Associated with| = 79654002|Edema|" using v2.0 of SCG
    • http://snomed.info/scg/404684003%3A47429007%3D79654002/syntaxVersion/2.0 
  • The expression "404684003 |Clinical finding|: 47429007 |Associated with| = 79654002|Edema|" based on the 20160731 international release and using v2.0 of SCG
    
    • http://snomed.info/sct/900000000000207008/version/20160731/scg/404684003%3A47429007%3D79654002/syntax/scg/version/2.0 
      
• ECL - Expression Constraint
  • The expression constraint "< 404684003 |Clinical finding|: < 47429007 |Associated with| = < 79654002 |Edema|"
    • http://snomed.info/ecl/%3C404684003%3A%3C%3C47429007%3D%3C%3C79654002 
  • The expression constraint "< 404684003 |Clinical finding|: < 47429007 |Associated with| = < 79654002 |Edema|" based on the 20160731 international release
    •  http://snomed.info/sct/900000000000207008/version/20160731/ecl/%3C404684003%3A%3C%3C47429007%3D%3C%3C79654002
  • The expression constraint "< 404684003 |Clinical finding|: < 47429007 |Associated with| = < 79654002 |Edema|" using v1.2 of the ECL
    
    • http://snomed.info/ecl/%3C404684003%3A%3C%3C47429007%3D%3C%3C79654002/syntaxVersion/1.2
      
  • The expression constraint "< 404684003 |Clinical finding|: < 47429007 |Associated with| = < 79654002 |Edema|" based on the 20160731 international release and using v1.2 of the ECL
    
    • http://snomed.info/sct/900000000000207008/version/20160731/ecl/%3C404684003%3A%3C%3C47429007%3D%3C%3C79654002/syntaxVersion/1.2
      
• QRL - Query
  • To be completed
• ETL - Expression Template
  • To be completed
• CTL - Expression Constraint Template
  • To be completed
• QTL - Query Template
  • To be completed

Note: %3A is “:”, %3C is “<”, %3D is “=”

URI Hexidecimal Characters

Characters represented as hexidecimal characters in SNOMED CT URIs (not for ".", "-", "_", "~"):

• %20  “ ”
• %21  “!”
• %22  “"”
• %23  “#”
• %24  “$”
• %25  “%”
• %26  “&”
• %27  “’”
• %28  “(“
• %29  “)”
• %2A  “*”
• %2B  “+”
• %2C  “,”
• %2F  “/”
• %3A  “:”
• %3B  “;”
• %3C  “<“
• %3D  “=“
• %3E  “>”
• %3F  “?”
• %40  “@”
• %5B  “[“
• %5C  “\”
• %5D  “]”
• %5E  “^”
• %60  “`”
• %7B  “{“
• %7C  “|”
• %7D  “}”