# Wikidata:Property proposal/official definition

### official definitionEdit

Description | the official definition for an item such as the General Conference of Weights and Measures definition for the International System of Units second, meter and kilogram |
---|---|

Represents | second (Q11574) |

Data type | String |

Template parameter | official definition by authoritative body and international agreement. |

Domain | item, property |

Example 1 | second (Q11574)-> "The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency , the unperturbed ground-state hyperfine transition frequency of the caesium atom, to be when expressed in the unit , which is equal to ." |

Example 2 | metre (Q11573)->"The metre, symbol m, is the SI unit of length. It is defined by taking the fixed
numerical value of the speed of light in vacuum, , to be when expressed in the unit , where the second is defined in terms of the caesium frequency ." |

Example 3 | kilogram (Q11570)->"The kilogram, symbol , is the SI unit of mass. It is defined by taking the fixed
numerical value of the Planck constant, , to be when expressed in the unit , which is equal to , where the metre and the second are defined interms of c and ∆νCs." |

Example 4 | ampere (Q25272)->"The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge, e, to be when expressed in the unit C, which is equal to A s, where the second is defined in terms of . |

}

." |planned use = I plan to use this for the second, meter, kilogram, ampere, kelvin, mole, and candela |number of ids = |expected completeness = |formatter URL = |external links = |see also = |robot and gadget jobs = |subpage = official definition |topic = generic |applicable stated in value = |single value constraint = |distinct values constraint = |Wikidata project = }}

#### MotivationEdit

I want to add the official definition for the SI units.WalkingRadiance (talk) 19:58, 3 July 2022 (UTC)

#### DiscussionEdit

**Disagree** Note that an "official definition" is sometimes in actuality about 12 pages long and not merely a sentence or two, because the definition is sometimes an amalgamation of all the constraints, secondary representations, etc. For example, hertz (Q39369), the caesium hyperfine frequency ΔνCs , can also be defined as https://www.bipm.org/documents/20126/69375160/199Hg_1129THz_2021.pdf/55fd06b5-0530-1a1c-42e6-129c121b2443 --Thadguidry (talk) 17:51, 4 July 2022 (UTC)

**Comment** And I think historically we have avoided storing official definitions in Wikidata; primarily the worry is about maintainability and keeping up with official definitions. So, instead of String, I think Thing would be better, and hence linking to official definitions is a better approach, where URI's are helpful for that. We certainly already have support for storing authority's information, as well as just linking out to SI official definitions by means of the already existing item, International System of Units (Q12457) and it's linking with described by source (P1343) to the current version which has the URL to the full work available at URL (P953). So, I don't think we need to store official documentation Strings in Wikidata (things in official documentation could change over time). Instead, it would be much better to use Linked Data approaches when feasible. Things, not Strings. If SI definitions are available in machine-readable format that can be addressed with a URI, then that would be a much better approach. I would encourage you instead to encourage BIPM to publish more Linked Data perhaps. --Thadguidry (talk) 17:51, 4 July 2022 (UTC)

**Comment** I agree with Thad. It would be preferable to link out to the official documentation/definition. UWashPrincipalCataloger (talk) 21:48, 5 July 2022 (UTC)