Tag¶

Individual classification labels - enabling precise data governance and discovery

Overview¶

The Tag entity represents an individual classification label within a hierarchical taxonomy. Tags are organized under Classifications and can have parent-child relationships, enabling precise categorization of data assets for governance, compliance, and discovery.

Relationship Diagram¶

graph TD
    %% Parent classification
    CLASS[Classification<br/>PII]

    %% Main tag entity
    CLASS -->|contains| TAG[Tag<br/>Sensitive]

    %% Parent tag relationship
    TAG_PARENT[Tag<br/>PersonalData] -.->|broader than| TAG

    %% Child tags
    TAG -->|has child| CHILD1[Tag<br/>Email]
    TAG -->|has child| CHILD2[Tag<br/>SSN]
    TAG -->|has child| CHILD3[Tag<br/>CreditCard]
    TAG -->|has child| CHILD4[Tag<br/>BankAccount]

    %% Grandchild tags
    CHILD1 -->|has child| GRAND1[Tag<br/>WorkEmail]
    CHILD1 -->|has child| GRAND2[Tag<br/>PersonalEmail]

    %% Sibling tags
    CLASS -->|contains| SIBLING1[Tag<br/>NonSensitive]
    SIBLING1 -->|has child| SIB_CHILD1[Tag<br/>Name]
    SIBLING1 -->|has child| SIB_CHILD2[Tag<br/>Address]

    %% Applied to columns
    TAG -.->|classifies| COL1[Column<br/>customer_email]
    CHILD1 -.->|classifies| COL2[Column<br/>user_email]
    CHILD1 -.->|classifies| COL3[Column<br/>contact_email]
    CHILD2 -.->|classifies| COL4[Column<br/>ssn]
    CHILD3 -.->|classifies| COL5[Column<br/>card_number]

    %% Applied to tables
    TAG -.->|classifies| TBL1[Table<br/>customer_pii]
    TAG -.->|classifies| TBL2[Table<br/>employee_data]

    %% Applied to other assets
    TAG -.->|classifies| DASH[Dashboard<br/>PII Report]
    TAG -.->|classifies| ML[MLModel<br/>pii_detector]
    TAG -.->|classifies| PIPE[Pipeline<br/>anonymization_job]

    %% Visual styling properties
    STYLE[Style Properties] -.->|color: #FF0000| TAG
    STYLE -.->|icon| TAG

    %% State indicators
    STATE1[Status<br/>Active] -.->|state| TAG

    %% Governance
    OWNER[User/Team] -.->|owns| TAG

    %% Styling
    classDef classification fill:#8B5CF6,stroke:#7C3AED,color:#fff
    classDef tag fill:#A78BFA,stroke:#8B5CF6,color:#fff
    classDef childTag fill:#DDD6FE,stroke:#A78BFA,color:#000
    classDef governance fill:#059669,stroke:#047857,color:#fff
    classDef data fill:#2563EB,stroke:#1E40AF,color:#fff
    classDef metadata fill:#F59E0B,stroke:#D97706,color:#fff

    class CLASS classification
    class TAG,SIBLING1,TAG_PARENT tag
    class CHILD1,CHILD2,CHILD3,CHILD4,GRAND1,GRAND2,SIB_CHILD1,SIB_CHILD2 childTag
    class OWNER,STATE1 governance
    class COL1,COL2,COL3,COL4,COL5,TBL1,TBL2,DASH,ML,PIPE data
    class STYLE metadata

Schema Specifications¶

View the complete Tag schema in your preferred format:

JSON SchemaRDFJSON-LD

Complete JSON Schema Definition

{
  "$id": "https://open-metadata.org/schema/entity/classification/tag.json",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Tag",
  "$comment": "@om-entity-type",
  "description": "A `Tag` entity is used for classification or categorization. It is a term defined under `Classification` entity. Tags are used to label the entities and entity fields, such as Tables, and Columns.",
  "type": "object",
  "javaType": "org.openmetadata.schema.entity.classification.Tag",
  "javaInterfaces": [
    "org.openmetadata.schema.EntityInterface"
  ],

  "definitions": {},

  "properties": {
    "id": {
      "description": "Unique identifier of this entity instance.",
      "$ref": "../../type/basic.json#/definitions/uuid"
    },
    "name": {
      "description": "Name of the tag.",
      "$ref": "../../type/basic.json#/definitions/entityName"
    },
    "displayName": {
      "description": "Display Name that identifies this tag.",
      "type": "string"
    },
    "fullyQualifiedName": {
      "description": "Unique name of the tag of format `Classification.tag1.tag2`.",
      "type": "string"
    },
    "description": {
      "description": "Description of the tag.",
      "$ref": "../../type/basic.json#/definitions/markdown"
    },
    "style": {
      "$ref": "../../type/basic.json#/definitions/style"
    },
    "classification": {
      "description": "Reference to the classification that this tag is part of.",
      "$ref": "../../type/entityReference.json"
    },
    "parent": {
      "description": "Reference to the parent tag. When null, the term is at the root of the Classification.",
      "$ref": "../../type/entityReference.json"
    },
    "children": {
      "description": "Children tags under this tag.",
      "$ref": "../../type/entityReferenceList.json"
    },
    "version": {
      "description": "Metadata version of the entity.",
      "$ref": "../../type/entityHistory.json#/definitions/entityVersion"
    },
    "updatedAt": {
      "description": "Last update time corresponding to the new version of the entity in Unix epoch time milliseconds.",
      "$ref": "../../type/basic.json#/definitions/timestamp"
    },
    "updatedBy": {
      "description": "User who made the update.",
      "type": "string"
    },
    "impersonatedBy": {
      "description": "Bot user that performed the action on behalf of the actual user.",
      "$ref": "../../type/basic.json#/definitions/impersonatedBy"
    },
    "href": {
      "description": "Link to the resource corresponding to the tag.",
      "$ref": "../../type/basic.json#/definitions/href"
    },
    "usageCount": {
      "description": "Count of how many times this tag and children tags are used.",
      "type": "integer"
    },
    "deprecated": {
      "description": "If the tag is deprecated.",
      "type": "boolean",
      "default": false
    },
    "deleted": {
      "description": "When `true` indicates the entity has been soft deleted.",
      "type": "boolean",
      "default": false
    },
    "changeDescription": {
      "description": "Change that lead to this version of the entity.",
      "$ref": "../../type/entityHistory.json#/definitions/changeDescription"
    },
    "incrementalChangeDescription": {
      "description": "Change that lead to this version of the entity.",
      "$ref": "../../type/entityHistory.json#/definitions/changeDescription"
    },
    "provider": {
      "$ref": "../../type/basic.json#/definitions/providerType"
    },
    "disabled": {
      "description": "System tags can't be deleted. Use this flag to disable them.",
      "type": "boolean",
      "default": false
    },
    "mutuallyExclusive": {
      "description": "Children tags under this group are mutually exclusive. When mutually exclusive is `true` the tags from this group are used to **classify** an entity. An entity can only be in one class - example, it can only be either `tier1` or `tier2` and not both. When mutually exclusive is `false`, the tags from this group are used to **categorize** an entity. An entity can be in multiple categories simultaneously - example a customer can be `newCustomer` and `atRisk` simultaneously.",
      "type": "boolean",
      "default": "false"
    },
    "domains": {
      "description": "Domains the asset belongs to. When not set, the asset inherits the domain from the parent it belongs to.",
      "$ref": "../../type/entityReferenceList.json"
    },
    "dataProducts": {
      "description": "List of data products this entity is part of.",
      "$ref": "../../type/entityReferenceList.json"
    },
    "owners": {
      "description": "Owners of this glossary term.",
      "$ref": "../../type/entityReferenceList.json"
    },
    "reviewers": {
      "description": "User references of the reviewers for this tag.",
      "$ref": "../../type/entityReferenceList.json"
    },
    "entityStatus": {
      "description": "Status of the tag.",
      "$ref": "../../type/status.json"
    },
    "recognizers": {
      "description": "List of recognizers configured for automatic detection of this tag",
      "type": "array",
      "items": {
        "$ref": "../../type/recognizer.json"
      }
    },
    "autoClassificationEnabled": {
      "description": "Whether automatic classification is enabled for this tag",
      "type": "boolean",
      "default": false
    },
    "autoClassificationPriority": {
      "description": "Priority for conflict resolution when multiple tags match (higher number = higher priority)",
      "type": "integer",
      "minimum": 0,
      "maximum": 100,
      "default": 50
    }
  },

  "required": ["id", "name", "description"]
}

View Full JSON Schema →

RDF/OWL Ontology Definition

@prefix om: <https://open-metadata.org/schema/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

# Tag Class Definition
om:Tag a owl:Class ;
    rdfs:subClassOf om:GovernanceAsset, skos:Concept ;
    rdfs:label "Tag" ;
    rdfs:comment "A Tag entity is used for classification or categorization. It is a term defined under Classification entity. Tags are used to label the entities and entity fields, such as Tables, and Columns." ;
    om:hierarchyLevel 2 .

# Datatype Properties
om:tagName a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:string ;
    rdfs:label "name" ;
    rdfs:comment "Name of the tag" ;
    owl:equivalentProperty skos:prefLabel .

om:displayName a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:string ;
    rdfs:label "displayName" ;
    rdfs:comment "Display Name that identifies this tag" .

om:fullyQualifiedName a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:string ;
    rdfs:label "fullyQualifiedName" ;
    rdfs:comment "Unique name of the tag of format Classification.tag1.tag2" ;
    owl:equivalentProperty skos:notation .

om:tagDescription a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:string ;
    rdfs:label "description" ;
    rdfs:comment "Description of the tag" ;
    owl:equivalentProperty skos:definition .

om:isDisabled a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:boolean ;
    rdfs:label "disabled" ;
    rdfs:comment "System tags can't be deleted. Use this flag to disable them" .

om:isDeprecated a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:boolean ;
    rdfs:label "deprecated" ;
    rdfs:comment "If the tag is deprecated" .

om:isDeleted a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:boolean ;
    rdfs:label "deleted" ;
    rdfs:comment "When true indicates the entity has been soft deleted" .

om:usageCount a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:integer ;
    rdfs:label "usageCount" ;
    rdfs:comment "Count of how many times this tag and children tags are used" .

om:mutuallyExclusive a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:boolean ;
    rdfs:label "mutuallyExclusive" ;
    rdfs:comment "Children tags under this group are mutually exclusive" .

om:autoClassificationEnabled a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:boolean ;
    rdfs:label "autoClassificationEnabled" ;
    rdfs:comment "Whether automatic classification is enabled for this tag" .

om:autoClassificationPriority a owl:DatatypeProperty ;
    rdfs:domain om:Tag ;
    rdfs:range xsd:integer ;
    rdfs:label "autoClassificationPriority" ;
    rdfs:comment "Priority for conflict resolution when multiple tags match (higher number = higher priority)" .

# Object Properties
om:belongsToClassification a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:Classification ;
    rdfs:label "belongsToClassification" ;
    rdfs:comment "Reference to the classification that this tag is part of" ;
    owl:equivalentProperty skos:inScheme .

om:hasParentTag a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:Tag ;
    rdfs:label "hasParentTag" ;
    rdfs:comment "Reference to the parent tag. When null, the term is at the root of the Classification" ;
    owl:equivalentProperty skos:broader .

om:hasChildTag a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:Tag ;
    rdfs:label "hasChildTag" ;
    rdfs:comment "Children tags under this tag" ;
    owl:equivalentProperty skos:narrower .

om:hasOwner a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:EntityReference ;
    rdfs:label "hasOwner" ;
    rdfs:comment "Owners of this tag" .

om:hasDomain a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:Domain ;
    rdfs:label "hasDomain" ;
    rdfs:comment "Domains the asset belongs to" .

om:hasDataProduct a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:DataProduct ;
    rdfs:label "hasDataProduct" ;
    rdfs:comment "Data products this entity is part of" .

om:hasReviewer a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:EntityReference ;
    rdfs:label "hasReviewer" ;
    rdfs:comment "User references of the reviewers for this tag" .

om:hasRecognizer a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:Recognizer ;
    rdfs:label "hasRecognizer" ;
    rdfs:comment "List of recognizers configured for automatic detection of this tag" .

om:appliedTo a owl:ObjectProperty ;
    rdfs:domain om:Tag ;
    rdfs:range om:DataAsset ;
    rdfs:label "appliedTo" ;
    rdfs:comment "Data assets tagged with this tag" .

# Example Instances
ex:sensitiveTag a om:Tag, skos:Concept ;
    skos:prefLabel "Sensitive" ;
    om:displayName "Sensitive PII" ;
    om:fullyQualifiedName "PII.Sensitive" ;
    skos:definition "Highly sensitive personal information requiring strict access controls and encryption" ;
    skos:inScheme ex:piiClassification ;
    om:isDisabled false ;
    om:isDeprecated false ;
    om:isDeleted false ;
    om:usageCount 342 ;
    skos:narrower ex:emailTag ;
    skos:narrower ex:ssnTag .

ex:emailTag a om:Tag, skos:Concept ;
    skos:prefLabel "Email" ;
    om:displayName "Email Address" ;
    om:fullyQualifiedName "PII.Sensitive.Email" ;
    skos:definition "Email addresses requiring privacy protection" ;
    skos:inScheme ex:piiClassification ;
    skos:broader ex:sensitiveTag ;
    om:usageCount 127 ;
    om:appliedTo ex:emailColumn .

View Full RDF Ontology →

JSON-LD Context and Example

{
  "@context": {
    "@vocab": "https://open-metadata.org/schema/",
    "om": "https://open-metadata.org/schema/",
    "skos": "http://www.w3.org/2004/02/skos/core#",
    "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
    "xsd": "http://www.w3.org/2001/XMLSchema#",

    "Tag": "om:Tag",
    "Concept": "skos:Concept",
    "name": {
      "@id": "skos:prefLabel",
      "@type": "xsd:string"
    },
    "fullyQualifiedName": {
      "@id": "skos:notation",
      "@type": "xsd:string"
    },
    "displayName": {
      "@id": "om:displayName",
      "@type": "xsd:string"
    },
    "description": {
      "@id": "skos:definition",
      "@type": "xsd:string"
    },
    "classification": {
      "@id": "skos:inScheme",
      "@type": "@id"
    },
    "parent": {
      "@id": "skos:broader",
      "@type": "@id"
    },
    "children": {
      "@id": "skos:narrower",
      "@type": "@id",
      "@container": "@set"
    },
    "disabled": {
      "@id": "om:isDisabled",
      "@type": "xsd:boolean"
    },
    "deprecated": {
      "@id": "om:isDeprecated",
      "@type": "xsd:boolean"
    },
    "deleted": {
      "@id": "om:isDeleted",
      "@type": "xsd:boolean"
    },
    "usageCount": {
      "@id": "om:usageCount",
      "@type": "xsd:integer"
    },
    "mutuallyExclusive": {
      "@id": "om:mutuallyExclusive",
      "@type": "xsd:boolean"
    },
    "owners": {
      "@id": "om:hasOwner",
      "@type": "@id",
      "@container": "@set"
    },
    "domains": {
      "@id": "om:hasDomain",
      "@type": "@id",
      "@container": "@set"
    },
    "dataProducts": {
      "@id": "om:hasDataProduct",
      "@type": "@id",
      "@container": "@set"
    },
    "reviewers": {
      "@id": "om:hasReviewer",
      "@type": "@id",
      "@container": "@set"
    },
    "recognizers": {
      "@id": "om:hasRecognizer",
      "@type": "@id",
      "@container": "@set"
    },
    "autoClassificationEnabled": {
      "@id": "om:autoClassificationEnabled",
      "@type": "xsd:boolean"
    },
    "autoClassificationPriority": {
      "@id": "om:autoClassificationPriority",
      "@type": "xsd:integer"
    }
  }
}

Example JSON-LD Instance:

{
  "@context": "https://open-metadata.org/context/tag.jsonld",
  "@type": ["Tag", "Concept"],
  "@id": "https://open-metadata.org/tags/PII/Sensitive/Email",

  "name": "Email",
  "fullyQualifiedName": "PII.Sensitive.Email",
  "displayName": "Email Address",
  "description": "# Email Address Tag\n\nIdentifies data containing email addresses.\n\n## Usage\n- Applied to columns storing email addresses\n- Triggers privacy protection measures\n- Subject to GDPR right to erasure",

  "classification": {
    "@id": "https://open-metadata.org/classifications/PII",
    "@type": "Classification",
    "name": "PII"
  },

  "parent": {
    "@id": "https://open-metadata.org/tags/PII/Sensitive",
    "@type": "Tag",
    "name": "Sensitive",
    "fullyQualifiedName": "PII.Sensitive"
  },

  "children": [],

  "style": {
    "color": "#FF6600",
    "iconURL": "https://example.com/icons/email.svg"
  },

  "disabled": false,
  "deprecated": false,
  "deleted": false,
  "usageCount": 127,
  "mutuallyExclusive": false,

  "owners": [
    {
      "@id": "https://open-metadata.org/users/admin",
      "@type": "User",
      "name": "admin"
    }
  ],

  "domains": [],
  "dataProducts": [],
  "reviewers": [],

  "recognizers": [
    {
      "@type": "Recognizer",
      "name": "email_pattern",
      "patternType": "regex",
      "pattern": "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}"
    }
  ],

  "autoClassificationEnabled": true,
  "autoClassificationPriority": 75
}

View Full JSON-LD Context →

Use Cases¶

Tag tables and columns with governance classifications (PII, PHI, etc.)
Apply data tier labels (Gold, Silver, Bronze)
Mark data quality levels
Label compliance requirements (GDPR, HIPAA, PCI-DSS)
Enable faceted search and filtering
Automate data policies based on tags
Track tag usage across data assets
Deprecate tags while maintaining history
Create custom domain-specific taxonomies
Support automated tag propagation (column → table)

JSON Schema Specification¶

Core Properties¶

`id` (uuid)¶

Type: string (UUID format) Required: Yes (system-generated) Description: Unique identifier of this entity instance.

{
  "id": "4d5e6f7a-8b9c-4d0e-1f2a-3b4c5d6e7f8a"
}

`name` (entityName)¶

Type: string Required: Yes Pattern: ^[^.]*$ (no dots allowed) Min Length: 1 Max Length: 256 Description: Name of the tag.

{
  "name": "Email"
}

`fullyQualifiedName`¶

Type: string Required: No (system-generated) Description: Unique name of the tag of format Classification.tag1.tag2.

{
  "fullyQualifiedName": "PII.Sensitive.Email"
}

`displayName`¶

Type: string Required: No Description: Display Name that identifies this tag.

{
  "displayName": "Email Address"
}

`description` (markdown)¶

Type: string (Markdown format) Required: Yes Description: Description of the tag.

{
  "description": "# Email Address Tag\n\nIdentifies data containing email addresses.\n\n## Usage Guidelines\n- Applied to columns storing email addresses\n- Triggers privacy protection measures\n- Subject to GDPR right to erasure\n\n## Examples\n- user_email\n- contact_email\n- billing_email"
}

Relationship Properties¶

`classification` (EntityReference)¶

Type: object Required: No Description: Reference to the classification that this tag is part of.

{
  "classification": {
    "id": "classification-uuid",
    "type": "classification",
    "name": "PII",
    "fullyQualifiedName": "PII"
  }
}

`parent` (EntityReference)¶

Type: object Required: No Description: Reference to the parent tag. When null, the term is at the root of the Classification.

{
  "parent": {
    "id": "parent-tag-uuid",
    "type": "tag",
    "name": "Sensitive",
    "fullyQualifiedName": "PII.Sensitive"
  }
}

`children` (EntityReferenceList)¶

Type: array of Tag references Required: No Description: Children tags under this tag.

{
  "children": [
    {
      "id": "child-tag-uuid-1",
      "type": "tag",
      "name": "WorkEmail",
      "fullyQualifiedName": "PII.Sensitive.Email.WorkEmail"
    },
    {
      "id": "child-tag-uuid-2",
      "type": "tag",
      "name": "PersonalEmail",
      "fullyQualifiedName": "PII.Sensitive.Email.PersonalEmail"
    }
  ]
}

Visual Properties¶

`style` (Style)¶

Type: object Required: No Reference: ../../type/basic.json#/definitions/style Description: Visual styling for displaying the tag

Style Object:

Property	Type	Required	Description
`color`	string	No	Hex color code (e.g., "#FF6600")
`iconURL`	uri	No	URL to tag icon image

{
  "style": {
    "color": "#FF6600",
    "iconURL": "https://example.com/icons/email.svg"
  }
}

Common Color Schemes:

Red (#FF0000): High sensitivity, critical
Orange (#FF6600): Medium sensitivity
Yellow (#FFCC00): Low sensitivity
Green (#00CC00): Public, non-sensitive
Blue (#0066FF): Informational
Purple (#9933FF): Compliance-related

State Properties¶

`disabled` (boolean)¶

Type: boolean Required: No (default: false) Description: System tags can't be deleted. Use this flag to disable them.

{
  "disabled": false
}

`deprecated` (boolean)¶

Type: boolean Required: No (default: false) Description: If the tag is deprecated.

{
  "deprecated": false
}

`deleted` (boolean)¶

Type: boolean Required: No (default: false) Description: When true indicates the entity has been soft deleted.

{
  "deleted": false
}

`mutuallyExclusive` (boolean)¶

Type: boolean Required: No (default: false) Description: Children tags under this group are mutually exclusive. When mutually exclusive is true the tags from this group are used to classify an entity. An entity can only be in one class - example, it can only be either tier1 or tier2 and not both. When mutually exclusive is false, the tags from this group are used to categorize an entity. An entity can be in multiple categories simultaneously - example a customer can be newCustomer and atRisk simultaneously.

{
  "mutuallyExclusive": false
}

Usage Properties¶

`usageCount` (integer)¶

Type: integer Required: No (system-generated) Description: Count of how many times this tag and children tags are used.

{
  "usageCount": 127
}

Governance Properties¶

`owners` (EntityReferenceList)¶

Type: array of EntityReference Required: No Description: Owners of this glossary term.

{
  "owners": [
    {
      "id": "user-uuid",
      "type": "user",
      "name": "admin"
    }
  ]
}

`domains` (EntityReferenceList)¶

Type: array of EntityReference Required: No Description: Domains the asset belongs to. When not set, the asset inherits the domain from the parent it belongs to.

{
  "domains": [
    {
      "id": "domain-uuid",
      "type": "domain",
      "name": "Marketing"
    }
  ]
}

`dataProducts` (EntityReferenceList)¶

Type: array of EntityReference Required: No Description: List of data products this entity is part of.

{
  "dataProducts": [
    {
      "id": "product-uuid",
      "type": "dataProduct",
      "name": "CustomerAnalytics"
    }
  ]
}

`reviewers` (EntityReferenceList)¶

Type: array of EntityReference Required: No Description: User references of the reviewers for this tag.

{
  "reviewers": [
    {
      "id": "user-uuid",
      "type": "user",
      "name": "data-steward"
    }
  ]
}

`entityStatus` (Status)¶

Type: object Required: No Reference: ../../type/status.json Description: Status of the tag.

{
  "entityStatus": "Active"
}

Auto-Classification Properties¶

`recognizers` (Recognizer[])¶

Type: array of Recognizer objects Required: No Description: List of recognizers configured for automatic detection of this tag

{
  "recognizers": [
    {
      "name": "email_pattern",
      "patternType": "regex",
      "pattern": "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}"
    }
  ]
}

`autoClassificationEnabled` (boolean)¶

Type: boolean Required: No (default: false) Description: Whether automatic classification is enabled for this tag

{
  "autoClassificationEnabled": true
}

`autoClassificationPriority` (integer)¶

Type: integer Required: No (default: 50) Min: 0 Max: 100 Description: Priority for conflict resolution when multiple tags match (higher number = higher priority)

{
  "autoClassificationPriority": 75
}

Versioning Properties¶

`version` (entityVersion)¶

Type: number Required: No (system-managed) Description: Metadata version of the entity.

{
  "version": 1.3
}

`updatedAt` (timestamp)¶

Type: integer (Unix epoch milliseconds) Required: No (system-managed) Description: Last update time corresponding to the new version of the entity in Unix epoch time milliseconds.

{
  "updatedAt": 1704240000000
}

`updatedBy` (string)¶

Type: string Required: No (system-managed) Description: User who made the update.

{
  "updatedBy": "admin"
}

`impersonatedBy` (impersonatedBy)¶

Type: object Required: No Reference: ../../type/basic.json#/definitions/impersonatedBy Description: Bot user that performed the action on behalf of the actual user.

{
  "impersonatedBy": {
    "id": "bot-uuid",
    "type": "bot",
    "name": "ingestion-bot"
  }
}

`href` (href)¶

Type: string (URI) Required: No (system-generated) Reference: ../../type/basic.json#/definitions/href Description: Link to the resource corresponding to the tag.

{
  "href": "https://open-metadata.org/api/v1/tags/PII.Sensitive.Email"
}

`changeDescription` (changeDescription)¶

Type: object Required: No (system-managed) Reference: ../../type/entityHistory.json#/definitions/changeDescription Description: Change that lead to this version of the entity.

{
  "changeDescription": {
    "fieldsAdded": [],
    "fieldsUpdated": [
      {
        "name": "description",
        "oldValue": "Old description",
        "newValue": "New description"
      }
    ],
    "fieldsDeleted": []
  }
}

`incrementalChangeDescription` (changeDescription)¶

Type: object Required: No (system-managed) Reference: ../../type/entityHistory.json#/definitions/changeDescription Description: Change that lead to this version of the entity.

{
  "incrementalChangeDescription": {
    "fieldsAdded": [],
    "fieldsUpdated": [],
    "fieldsDeleted": []
  }
}

`provider` (providerType)¶

Type: string (enum) Required: No Reference: ../../type/basic.json#/definitions/providerType Description: Provider of the entity (e.g., "system", "user").

{
  "provider": "system"
}

Complete Example¶

Primary Tag with Children¶

{
  "id": "4d5e6f7a-8b9c-4d0e-1f2a-3b4c5d6e7f8a",
  "name": "Sensitive",
  "fullyQualifiedName": "PII.Sensitive",
  "displayName": "Sensitive PII",
  "description": "# Sensitive Personal Information\n\nHighly sensitive personal information requiring strict access controls and encryption.",
  "classification": {
    "id": "classification-uuid",
    "type": "classification",
    "name": "PII",
    "fullyQualifiedName": "PII"
  },
  "parent": null,
  "children": [
    {
      "id": "child-uuid-1",
      "type": "tag",
      "name": "Email",
      "fullyQualifiedName": "PII.Sensitive.Email"
    },
    {
      "id": "child-uuid-2",
      "type": "tag",
      "name": "SSN",
      "fullyQualifiedName": "PII.Sensitive.SSN"
    },
    {
      "id": "child-uuid-3",
      "type": "tag",
      "name": "CreditCard",
      "fullyQualifiedName": "PII.Sensitive.CreditCard"
    }
  ],
  "style": {
    "color": "#FF0000",
    "iconURL": "https://example.com/icons/sensitive.svg"
  },
  "disabled": false,
  "deprecated": false,
  "deleted": false,
  "mutuallyExclusive": false,
  "usageCount": 342,
  "owners": [],
  "domains": [],
  "dataProducts": [],
  "reviewers": [],
  "recognizers": [],
  "autoClassificationEnabled": false,
  "autoClassificationPriority": 50,
  "version": 1.3,
  "updatedAt": 1704240000000,
  "updatedBy": "admin",
  "href": "https://open-metadata.org/api/v1/tags/PII.Sensitive"
}

Nested Child Tag with Auto-Classification¶

{
  "id": "5e6f7a8b-9c0d-4e1f-2a3b-4c5d6e7f8a9b",
  "name": "Email",
  "fullyQualifiedName": "PII.Sensitive.Email",
  "displayName": "Email Address",
  "description": "Email addresses requiring privacy protection",
  "classification": {
    "id": "classification-uuid",
    "type": "classification",
    "name": "PII",
    "fullyQualifiedName": "PII"
  },
  "parent": {
    "id": "parent-uuid",
    "type": "tag",
    "name": "Sensitive",
    "fullyQualifiedName": "PII.Sensitive"
  },
  "children": [],
  "style": {
    "color": "#FF6600"
  },
  "disabled": false,
  "deprecated": false,
  "deleted": false,
  "mutuallyExclusive": false,
  "usageCount": 127,
  "owners": [
    {
      "id": "user-uuid",
      "type": "user",
      "name": "admin"
    }
  ],
  "domains": [],
  "dataProducts": [],
  "reviewers": [
    {
      "id": "steward-uuid",
      "type": "user",
      "name": "data-steward"
    }
  ],
  "recognizers": [
    {
      "name": "email_pattern",
      "patternType": "regex",
      "pattern": "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}",
      "confidence": 0.9
    }
  ],
  "autoClassificationEnabled": true,
  "autoClassificationPriority": 75,
  "version": 1.1,
  "updatedAt": 1704240000000,
  "updatedBy": "admin",
  "href": "https://open-metadata.org/api/v1/tags/PII.Sensitive.Email"
}

RDF Representation¶

Ontology Class¶

@prefix om: <https://open-metadata.org/schema/> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

om:Tag a owl:Class ;
    rdfs:subClassOf om:GovernanceAsset, skos:Concept ;
    rdfs:label "Tag" ;
    rdfs:comment "A Tag entity is used for classification or categorization. It is a term defined under Classification entity. Tags are used to label the entities and entity fields, such as Tables, and Columns." .

Instance Example¶

@prefix om: <https://open-metadata.org/schema/> .
@prefix ex: <https://open-metadata.org/tags/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

ex:PII_Sensitive a om:Tag, skos:Concept ;
    skos:prefLabel "Sensitive" ;
    om:displayName "Sensitive PII" ;
    skos:notation "PII.Sensitive" ;
    skos:definition "Highly sensitive personal information requiring strict access controls and encryption" ;
    skos:inScheme ex:PII ;
    om:isDisabled false ;
    om:isDeprecated false ;
    om:isDeleted false ;
    om:mutuallyExclusive false ;
    om:usageCount 342 ;
    om:autoClassificationEnabled false ;
    om:autoClassificationPriority 50 ;
    skos:narrower ex:PII_Sensitive_Email ;
    skos:narrower ex:PII_Sensitive_SSN .

ex:PII_Sensitive_Email a om:Tag, skos:Concept ;
    skos:prefLabel "Email" ;
    om:displayName "Email Address" ;
    skos:notation "PII.Sensitive.Email" ;
    skos:definition "Email addresses requiring privacy protection" ;
    skos:inScheme ex:PII ;
    skos:broader ex:PII_Sensitive ;
    om:isDisabled false ;
    om:isDeprecated false ;
    om:isDeleted false ;
    om:usageCount 127 ;
    om:autoClassificationEnabled true ;
    om:autoClassificationPriority 75 .

JSON-LD Context¶

{
  "@context": {
    "@vocab": "https://open-metadata.org/schema/",
    "om": "https://open-metadata.org/schema/",
    "skos": "http://www.w3.org/2004/02/skos/core#",
    "xsd": "http://www.w3.org/2001/XMLSchema#",
    "Tag": "om:Tag",
    "Concept": "skos:Concept",
    "name": {
      "@id": "skos:prefLabel",
      "@type": "xsd:string"
    },
    "displayName": {
      "@id": "om:displayName",
      "@type": "xsd:string"
    },
    "fullyQualifiedName": {
      "@id": "skos:notation",
      "@type": "xsd:string"
    },
    "description": {
      "@id": "skos:definition",
      "@type": "xsd:string"
    },
    "classification": {
      "@id": "skos:inScheme",
      "@type": "@id"
    },
    "parent": {
      "@id": "skos:broader",
      "@type": "@id"
    },
    "children": {
      "@id": "skos:narrower",
      "@type": "@id",
      "@container": "@set"
    },
    "disabled": {
      "@id": "om:isDisabled",
      "@type": "xsd:boolean"
    },
    "deprecated": {
      "@id": "om:isDeprecated",
      "@type": "xsd:boolean"
    },
    "deleted": {
      "@id": "om:isDeleted",
      "@type": "xsd:boolean"
    },
    "usageCount": {
      "@id": "om:usageCount",
      "@type": "xsd:integer"
    },
    "mutuallyExclusive": {
      "@id": "om:mutuallyExclusive",
      "@type": "xsd:boolean"
    },
    "owners": {
      "@id": "om:hasOwner",
      "@type": "@id",
      "@container": "@set"
    },
    "domains": {
      "@id": "om:hasDomain",
      "@type": "@id",
      "@container": "@set"
    },
    "dataProducts": {
      "@id": "om:hasDataProduct",
      "@type": "@id",
      "@container": "@set"
    },
    "reviewers": {
      "@id": "om:hasReviewer",
      "@type": "@id",
      "@container": "@set"
    },
    "recognizers": {
      "@id": "om:hasRecognizer",
      "@type": "@id",
      "@container": "@set"
    },
    "autoClassificationEnabled": {
      "@id": "om:autoClassificationEnabled",
      "@type": "xsd:boolean"
    },
    "autoClassificationPriority": {
      "@id": "om:autoClassificationPriority",
      "@type": "xsd:integer"
    }
  }
}

JSON-LD Example¶

{
  "@context": "https://open-metadata.org/context/tag.jsonld",
  "@type": ["Tag", "Concept"],
  "@id": "https://open-metadata.org/tags/PII/Sensitive/Email",
  "name": "Email",
  "displayName": "Email Address",
  "fullyQualifiedName": "PII.Sensitive.Email",
  "description": "Email addresses requiring privacy protection",
  "classification": {
    "@id": "https://open-metadata.org/classifications/PII",
    "@type": "Classification"
  },
  "parent": {
    "@id": "https://open-metadata.org/tags/PII/Sensitive",
    "@type": "Tag"
  },
  "children": [],
  "style": {
    "color": "#FF6600"
  },
  "disabled": false,
  "deprecated": false,
  "deleted": false,
  "mutuallyExclusive": false,
  "usageCount": 127,
  "owners": [
    {
      "@id": "https://open-metadata.org/users/admin",
      "@type": "User"
    }
  ],
  "domains": [],
  "dataProducts": [],
  "reviewers": [],
  "recognizers": [
    {
      "@type": "Recognizer",
      "name": "email_pattern",
      "patternType": "regex",
      "pattern": "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}"
    }
  ],
  "autoClassificationEnabled": true,
  "autoClassificationPriority": 75
}

Tag Hierarchies¶

PII Classification Example¶

PII
├── Sensitive
│   ├── Email
│   ├── SSN
│   ├── CreditCard
│   ├── BankAccount
│   └── Biometric
└── NonSensitive
    ├── Name
    ├── PhoneNumber
    ├── Address
    └── DateOfBirth

Tier Classification Example (Mutually Exclusive)¶

Tier
├── Gold
├── Silver
└── Bronze

Compliance Classification Example¶

Compliance
├── GDPR
│   ├── PersonalData
│   ├── SensitiveData
│   └── RightToErasure
├── HIPAA
│   ├── PHI
│   └── ePHI
└── PCI-DSS
    ├── CardholderData
    └── SensitiveAuthenticationData

Relationships¶

Parent Entities¶

Classification: The classification this tag belongs to
Tag: Parent tag (for nested tags)

Child Entities¶

Tag: Child tags in hierarchy

Associated Entities¶

DataAsset: Tables, columns, dashboards, etc. tagged with this tag
Column: Table columns with this tag
Table: Tables with this tag
Dashboard: Dashboards with this tag

Custom Properties¶

This entity supports custom properties through the extension field. Common custom properties include:

Data Classification: Sensitivity level
Cost Center: Billing allocation
Retention Period: Data retention requirements
Application Owner: Owning application/team

See Custom Properties for details on defining and using custom properties.

API Operations¶

Create Tag¶

POST /api/v1/classifications/{classificationId}/tags
Content-Type: application/json

{
  "name": "Email",
  "displayName": "Email Address",
  "description": "Email addresses requiring privacy protection",
  "parent": "PII.Sensitive",
  "style": {
    "color": "#FF6600"
  }
}

Get Tag¶

GET /api/v1/tags/name/PII.Sensitive.Email?fields=parent,children,usageCount

Update Tag¶

PATCH /api/v1/tags/{id}
Content-Type: application/json-patch+json

[
  {
    "op": "replace",
    "path": "/description",
    "value": "Updated description for email tag"
  },
  {
    "op": "replace",
    "path": "/style/color",
    "value": "#FF9900"
  }
]

Deprecate Tag¶

PATCH /api/v1/tags/{id}
Content-Type: application/json-patch+json

[
  {
    "op": "replace",
    "path": "/deprecated",
    "value": true
  }
]

Apply Tag to Table¶

PUT /api/v1/tables/{tableId}/tags
Content-Type: application/json

{
  "tags": [
    {
      "tagFQN": "PII.Sensitive.Email",
      "source": "Classification",
      "labelType": "Manual"
    }
  ]
}

Apply Tag to Column¶

PUT /api/v1/tables/{tableId}/columns/{columnName}/tags
Content-Type: application/json

{
  "tags": [
    {
      "tagFQN": "PII.Sensitive.Email",
      "source": "Classification",
      "labelType": "Manual"
    }
  ]
}

GET /api/v1/classifications/{classificationId}/tags?fields=parent,children,usageCount

Get Tag Usage¶

GET /api/v1/tags/name/PII.Sensitive.Email/usage

TagLabel Application¶

When a tag is applied to a data asset, it creates a TagLabel with additional metadata:

{
  "tagFQN": "PII.Sensitive.Email",
  "description": "Email addresses",
  "source": "Classification",
  "labelType": "Manual",
  "state": "Confirmed"
}

TagLabel Properties:

Property	Type	Description
`tagFQN`	string	Fully qualified tag name
`description`	string	Tag description (inherited)
`source`	enum	Source: `Classification`, `Glossary`
`labelType`	enum	Type: `Manual`, `Propagated`, `Automated`, `Derived`
`state`	enum	State: `Suggested`, `Confirmed`

Classification - Parent classification hierarchies
GlossaryTerm - Business terminology
Table - Applying tags to tables
Column - Applying tags to columns
SKOS Standard - W3C Simple Knowledge Organization System
Data Governance - Governance framework

Tag¶

Overview¶

Relationship Diagram¶

Schema Specifications¶

Use Cases¶

JSON Schema Specification¶

Core Properties¶

id (uuid)¶

name (entityName)¶

fullyQualifiedName¶

displayName¶

description (markdown)¶