Property talk:P1821

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Open Food Facts food category ID
represents a food category on Open Food Facts

Applicable "stated in" value	Open Food Facts (Q3353146)
Data type	External identifier
Domain	According to this template: food (Q2095), drink (Q40050) According to statements in the property: food (Q2095), drink (Q40050), taxon (Q16521), food ingredient (Q25403900), leaf vegetable (Q20134), fruit (Q3314483), berry (Q13184), citrus fruit (Q2574750), bean (Q379813) or organisms known by a particular common name (Q55983715) When possible, data should only be stored as statements
Allowed values	([a-z][a-z]):(([A-Za-z]+-?){5}?)
Example	apple juice (Q618355) → apple-juices noodle (Q192874) → noodle
Source	According to this template: Open Food Facts categories ( http://world.openfoodfacts.org/categories) which are created using a hand-curated taxonomy (http://en.wiki.openfoodfacts.org/Global_categories_taxonomy), which is regularly expanded based on new available products contributed by users. According to statements in the property: https://world.openfoodfacts.org/categories When possible, data should only be stored as statements
Formatter URL	https://world.openfoodfacts.org/category/$1
See also	Open Food Facts food additive ID (P1820), Open Food Facts ingredient ID (P5930)
Lists	Items with the most statements of this property Count of items by number of statements (chart) Items with the most statements Items with the fewest statements Count of items by number of sitelinks (chart) Items with the most sitelinks Items with the most sitelinks, but no link to one Wikipedia (sample: Welsh Wikipedia, cywiki) Items with the fewest sitelinks Most linked wikis Items with the most identifier properties Items with no other external identifier Items with no other statements Most recently created items Items with novalue claims Items with unknown value claims Usage history (total) Usage history (main statement) Chart by item creation date Mix'n'match (Report) Database reports/Constraint violations/P1821 Map Random list
Proposal discussion	Proposal discussion
Current uses	Total 1,368 Main statement 1,365 out of 2,051 (67% complete) 99.8% of uses Qualifier 2 0.1% of uses Reference 1 <0.1% of uses
Search for values

[create Create a translatable help page (preferably in English) for this property to be included here]

Single value: this property generally contains a single value. (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P1821#Single value, SPARQL

Distinct values: this property likely contains a value that is different from all other items. (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P1821#Unique value, SPARQL (every item), SPARQL (by value)

Type “food (Q2095), drink (Q40050), taxon (Q16521), food ingredient (Q25403900), leaf vegetable (Q20134), fruit (Q3314483), berry (Q13184), citrus fruit (Q2574750), bean (Q379813), organisms known by a particular common name (Q55983715)”: item must contain property “subclass of (P279)” with classes “food (Q2095), drink (Q40050), taxon (Q16521), food ingredient (Q25403900), leaf vegetable (Q20134), fruit (Q3314483), berry (Q13184), citrus fruit (Q2574750), bean (Q379813), organisms known by a particular common name (Q55983715)” or their subclasses (defined using subclass of (P279)). (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P1821#Type Q2095, Q40050, Q16521, Q25403900, Q20134, Q3314483, Q13184, Q2574750, Q379813, Q55983715, SPARQL

Format “([a-z][a-z]):(([A-Za-z]+-?){5}?)”: value must be formatted using this pattern (PCRE syntax). (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P1821#Format, SPARQL

Scope is as main value (Q54828448), as reference (Q54828450): the property must be used by specified way only (Help)

List of violations of this constraint: Database reports/Constraint violations/P1821#Scope, hourly updated report, SPARQL

Allowed entity types are Wikibase item (Q29934200): the property may only be used on a certain entity type (Help)

Exceptions are possible as rare values may exist. Exceptions can be specified using exception to constraint (P2303).
List of violations of this constraint: Database reports/Constraint violations/P1821#Entity types

This is the Open Food Facts food category, which represents a food category on Open Food Facts. A food category is as narrow as "Apple Pie" or as broad as "Wines", and list all instance of products. We support translations and synonyms, so we'll be able to better help enriching Wikidata and keep Open Food Fact's taxonomies more aligned with Wikidata.

Property available on Mix'n Match

The property available for matching on Mix'n Match --Teolemon (talk) 09:37, 30 April 2016 (UTC)

use for taxons?

should we use this for plants and animals? Q158994#P1821 is a grass. i suppose the food part is only the grain of the grass (i'm not an expert). I'd argure this should be a separate (subclass of food product (Q951964)) entity--Shisma (talk) 14:15, 16 February 2020 (UTC)

Ping @Teolemon:

Canonical URL and IDs use language prefix

The ID appears to be tied to a language if one looks at the canonical URL for these IDs - the format should be lang : ID such as en:nutmeg while the page title are just the language. This language prefix format is supported by the https://wiki.openfoodfacts.org/Global_taxonomies#Wikidata section. Will improve the constraint. Wolfgang8741 (talk) 19:18, 16 September 2022 (UTC)