# Heritage Custodian Storage Ontology (hc-storage)

**Version:** 1.0.0  
**Namespace:** `https://nde.nl/ontology/hc/`  
**Prefix:** `hc:`  
**Location:** `frontend/public/ontology/hc-storage.ttl`  
**Created:** 2026-01-02  
**License:** CC BY 4.0

## Overview

The Heritage Custodian Storage Ontology (`hc-storage`) is an extension ontology for modeling heritage storage facilities, environmental zones, storage units, and preservation activities. It extends CIDOC-CRM with specialized classes and properties for heritage collection storage management.

### Purpose

This ontology addresses the need to:

1. **Model storage infrastructure** - Facilities, zones, and units where heritage collections are preserved
2. **Track environmental conditions** - Temperature, humidity, light levels, and other factors affecting preservation
3. **Document storage activities** - Assignments, relocations, and custody transfers
4. **Integrate sensor data** - SOSA/SSN compatible environmental monitoring
5. **Support preservation planning** - Environmental requirements and compliance tracking

### Base Ontology Alignments

| Ontology | Usage |
|----------|-------|
| **CIDOC-CRM v7.1.3** | Core classes and predicates for cultural heritage |
| **SOSA/SSN** | Environmental sensor observations |
| **PROV-O** | Provenance and activity tracking |
| **RiC-O** | Records in Contexts for archival storage |
| **PREMIS** | Preservation metadata |

---

## Class Hierarchy

```
owl:Thing
  │
  ├── crm:E27_Site (Physical Place)
  │     ├── hc:StorageFacility
  │     ├── hc:EnvironmentalZone
  │     └── hc:StorageUnit
  │
  ├── crm:E7_Activity (Activity)
  │     └── hc:StorageAssignment
  │
  ├── crm:E9_Move (Movement)
  │     └── hc:StorageRelocation
  │
  ├── crm:E10_Transfer_of_Custody
  │     └── hc:StorageCustodyTransfer
  │
  ├── crm:E14_Condition_Assessment
  │     └── hc:StorageConditionAssessment
  │
  ├── crm:E29_Design_or_Procedure
  │     └── hc:EnvironmentalRequirement
  │
  ├── crm:E54_Dimension
  │     └── hc:StorageCapacitySpecification
  │
  ├── sosa:Observation
  │     └── hc:StorageEnvironmentObservation
  │
  └── sosa:Platform
        └── hc:EnvironmentalSensorPlatform
```

---

## Classes

### Storage Location Classes

#### hc:StorageFacility

A dedicated facility for storing heritage objects (museum depot, archive repository, library stack).

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E27_Site` | Physical location |
| Related Concepts | `schema:SelfStorage`, `wd:Q35127` (warehouse), `aat:300005534` (storage buildings) |

**Key Relationships:**
- Contains `hc:EnvironmentalZone` via `hc:hasStorageSection`
- Contains `hc:StorageUnit` via `hc:hasStorageSection`
- Stores objects via `hc:currentlyStores`

---

#### hc:EnvironmentalZone

A climate-controlled area within a storage facility with specific environmental parameters.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E27_Site` | Physical location |
| Related Concepts | `wd:Q1759899` (climate control), `aat:300265612` (climate control technique) |

**Environmental Parameters:**
- Target temperature (°C)
- Temperature tolerance (±°C)
- Target relative humidity (%)
- Humidity tolerance (±%)
- Maximum light level (lux)
- Maximum annual light exposure (lux-hours)

---

#### hc:StorageUnit

An individual storage compartment, shelf, cabinet, drawer, or other discrete unit.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E27_Site` | Physical location |
| Related Concepts | `wd:Q1186447` (storage unit), `aat:300038892` (storage containers) |

**Location Attributes:**
- Row number
- Bay number
- Shelf number
- Local identifier/barcode

---

### Activity Classes

#### hc:StorageAssignment

The activity of assigning a heritage object to a specific storage location.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E7_Activity` | General activity |
| Related Concepts | `aat:300054711` (storage activity) |

---

#### hc:StorageRelocation

The movement of a heritage object from one storage location to another.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E9_Move` | Movement event |
| Related Concepts | `aat:300054644` (relocation) |

**Uses CIDOC-CRM predicates:**
- `crm:P26_moved_to` (destination)
- `crm:P27_moved_from` (origin)

---

#### hc:StorageCustodyTransfer

Transfer of physical custody responsibility for stored heritage objects.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E10_Transfer_of_Custody` | Custody transfer |
| Related Concepts | `rico:InstantiationToInstantiationRelation` |

**Uses CIDOC-CRM predicates:**
- `crm:P28_custody_surrendered_by`
- `crm:P29_custody_received_by`
- `crm:P30_transferred_custody_of`

---

#### hc:StorageConditionAssessment

An assessment of environmental conditions and suitability of a storage location.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E14_Condition_Assessment` | Condition assessment |
| Related Concepts | `aat:300054642` (condition assessment) |

---

### Environmental Monitoring Classes (SOSA Integration)

#### hc:StorageEnvironmentObservation

An observation of environmental conditions in a storage location.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `sosa:Observation` | Sensor observation |

**SOSA Semantics:**
- Storage location is `sosa:FeatureOfInterest`
- Environmental property is `sosa:ObservableProperty`

---

#### hc:EnvironmentalSensorPlatform

A platform hosting environmental monitoring sensors in a storage facility.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `sosa:Platform` | Sensor platform |

**Examples:** Data loggers (Hanwell, Meaco), building management systems, IoT sensor networks

---

### Specification Classes

#### hc:EnvironmentalRequirement

A specification of environmental conditions required for safe storage.

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E29_Design_or_Procedure` | Design/procedure |
| Related Concepts | `aat:300265612` (climate control technique) |

---

#### hc:StorageCapacitySpecification

A measurement of storage capacity (linear meters, cubic meters, item count).

| Property | Type | Description |
|----------|------|-------------|
| Parent Class | `crm:E54_Dimension` | Dimension |

---

## Properties

### Location Relationships

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:hasStorageSection` | `StorageFacility` | `EnvironmentalZone` \| `StorageUnit` | Links facility to sections (subprop of `crm:P59_has_section`) |
| `hc:isStorageSectionOf` | `EnvironmentalZone` \| `StorageUnit` | `StorageFacility` | Inverse of hasStorageSection |
| `hc:currentlyStores` | Storage locations | `crm:E18_Physical_Thing` | Objects currently stored (subprop of `crm:P55`) |
| `hc:isStoredIn` | `crm:E18_Physical_Thing` | Storage locations | Object's current location |
| `hc:hasPermanentStorageLocation` | `crm:E18_Physical_Thing` | Storage locations | Designated permanent location (subprop of `crm:P54`) |

### Environmental Properties

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:hasEnvironmentalRequirement` | Zone/Object/Collection | `EnvironmentalRequirement` | Required conditions |
| `hc:meetsRequirement` | Storage locations | `EnvironmentalRequirement` | Compliance indicator |
| `hc:hasEnvironmentalObservation` | Zone/Assessment | `StorageEnvironmentObservation` | Sensor observations |
| `hc:monitoredByPlatform` | `EnvironmentalZone` | `EnvironmentalSensorPlatform` | Monitoring system |

### Environmental Parameter Properties (Datatype)

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:targetTemperature` | `EnvironmentalRequirement` | `xsd:decimal` | Target temp (°C) |
| `hc:temperatureTolerance` | `EnvironmentalRequirement` | `xsd:decimal` | Tolerance (±°C) |
| `hc:targetRelativeHumidity` | `EnvironmentalRequirement` | `xsd:decimal` | Target RH (%) |
| `hc:relativeHumidityTolerance` | `EnvironmentalRequirement` | `xsd:decimal` | Tolerance (±%) |
| `hc:maxLightLevel` | `EnvironmentalRequirement` | `xsd:decimal` | Max light (lux) |
| `hc:maxAnnualLightExposure` | `EnvironmentalRequirement` | `xsd:decimal` | Max annual (lux-hours) |

### Storage Unit Attributes

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:storageUnitIdentifier` | `StorageUnit` | `xsd:string` | Local ID/barcode |
| `hc:storageUnitType` | `StorageUnit` | `crm:E55_Type` | Unit type |
| `hc:rowNumber` | `StorageUnit` | `xsd:string` | Row/aisle ID |
| `hc:bayNumber` | `StorageUnit` | `xsd:string` | Bay/section ID |
| `hc:shelfNumber` | `StorageUnit` | `xsd:integer` | Shelf level |

### Capacity Properties

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:hasStorageCapacity` | Storage locations | `StorageCapacitySpecification` | Capacity spec |
| `hc:totalCapacityValue` | `StorageCapacitySpecification` | `xsd:decimal` | Total capacity |
| `hc:availableCapacityValue` | `StorageCapacitySpecification` | `xsd:decimal` | Available capacity |
| `hc:capacityUnit` | `StorageCapacitySpecification` | `crm:E58_Measurement_Unit` | Unit of measure |

### Assignment Properties

| Property | Domain | Range | Description |
|----------|--------|-------|-------------|
| `hc:assignedToLocation` | `StorageAssignment` | Storage locations | Target location |
| `hc:assignedObject` | `StorageAssignment` | `crm:E18_Physical_Thing` | Object assigned |
| `hc:assignmentReason` | `StorageAssignment` | `xsd:string` | Reason for assignment |
| `hc:assignedBy` | `StorageAssignment` | `crm:E39_Actor` | Responsible agent |
| `hc:storageDocumentation` | Assignment/Relocation | `crm:E31_Document` | Related documentation |

---

## Named Individuals

### Storage Unit Types

| Individual | Label | Description | AAT/Wikidata |
|------------|-------|-------------|--------------|
| `hc:ArchiveBox` | Archive Box | Acid-free archival box | aat:300045703 |
| `hc:FlatFileDrawer` | Flat File Drawer | Drawer for oversized flat materials | aat:300038899 |
| `hc:HangingRack` | Hanging Rack | Rack for textiles/paintings | - |
| `hc:CompactShelving` | Compact Shelving | Mobile shelving (Compactus) | aat:300221807 |
| `hc:SpecimenCabinet` | Specimen Cabinet | Cabinet for specimens/artifacts | - |
| `hc:ColdStorageVault` | Cold Storage Vault | Refrigerated storage | wd:Q1199549 |

### Environmental Presets

| Individual | Label | Temp | RH | Light | Standard |
|------------|-------|------|-----|-------|----------|
| `hc:StandardArchiveEnvironment` | Standard Archive | 18°C ±2 | 50% ±5 | 50 lux | ISO 11799 |
| `hc:PhotographicMaterialsEnvironment` | Photographic | 15°C ±2 | 35% ±5 | 50 lux | ISO 18934 |
| `hc:ColdStorageEnvironment` | Cold Storage | -5°C ±3 | 30% ±5 | 0 lux | ISO 18911 |
| `hc:TextileStorageEnvironment` | Textile | 18°C ±2 | 50% ±5 | 50 lux, 15k lux-hr/yr | - |

---

## LinkML Integration

The ontology integrates with LinkML schema classes:

| LinkML Class | HC Ontology Class | File |
|--------------|-------------------|------|
| `Storage` | `hc:StorageFacility` | `Storage.yaml` |
| `StorageUnit` | `hc:StorageUnit` | `StorageUnit.yaml` |
| `EnvironmentalZone` | `hc:EnvironmentalZone` | `EnvironmentalZone.yaml` |
| `StorageCondition` | `hc:StorageConditionAssessment` | `StorageCondition.yaml` |
| `StorageConditionPolicy` | `hc:EnvironmentalRequirement` | `StorageConditionPolicy.yaml` |

### Enumeration Mappings

| LinkML Enum | HC Ontology Mapping |
|-------------|---------------------|
| `StorageUnitTypeEnum.ARCHIVE_BOX` | `hc:ArchiveBox` |
| `StorageUnitTypeEnum.FLAT_FILE_DRAWER` | `hc:FlatFileDrawer` |
| `StorageUnitTypeEnum.COMPACT_SHELVING` | `hc:CompactShelving` |
| `EnvironmentalZoneTypeEnum.ARCHIVE_STANDARD` | `hc:StandardArchiveEnvironment` |
| `EnvironmentalZoneTypeEnum.COLD_STORAGE` | `hc:ColdStorageEnvironment` |
| `EnvironmentalZoneTypeEnum.PHOTOGRAPHIC` | `hc:PhotographicMaterialsEnvironment` |

---

## Usage Examples

### Example 1: Storage Facility with Zones

```turtle
@prefix hc: <https://nde.nl/ontology/hc/> .
@prefix crm: <http://www.cidoc-crm.org/cidoc-crm/> .

<https://nde.nl/storage/na-depot-a> a hc:StorageFacility ;
    crm:P87_is_identified_by "Nationaal Archief Depot A"@nl ;
    hc:hasStorageSection <https://nde.nl/zone/na-depot-a-standard> ;
    hc:hasStorageSection <https://nde.nl/zone/na-depot-a-cold> .

<https://nde.nl/zone/na-depot-a-standard> a hc:EnvironmentalZone ;
    crm:P87_is_identified_by "Standard Archive Zone"@en ;
    hc:hasEnvironmentalRequirement hc:StandardArchiveEnvironment ;
    hc:isStorageSectionOf <https://nde.nl/storage/na-depot-a> .
```

### Example 2: Storage Unit Location

```turtle
<https://nde.nl/unit/na-r12-b3-s4> a hc:StorageUnit ;
    crm:P87_is_identified_by "Row 12, Bay 3, Shelf 4"@en ;
    hc:storageUnitIdentifier "NA-2024-BOX-00145" ;
    hc:storageUnitType hc:ArchiveBox ;
    hc:rowNumber "12" ;
    hc:bayNumber "3" ;
    hc:shelfNumber 4 ;
    hc:isStorageSectionOf <https://nde.nl/zone/na-depot-a-standard> ;
    hc:currentlyStores <https://nde.nl/object/doc-1234> .
```

### Example 3: Environmental Observation

```turtle
@prefix sosa: <http://www.w3.org/ns/sosa/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://nde.nl/obs/temp-2024-01-15> a hc:StorageEnvironmentObservation ;
    sosa:hasFeatureOfInterest <https://nde.nl/zone/na-depot-a-standard> ;
    sosa:observedProperty <http://example.org/temperature> ;
    sosa:hasSimpleResult "18.2"^^xsd:decimal ;
    sosa:resultTime "2024-01-15T10:00:00Z"^^xsd:dateTime .
```

---

## Environmental Standards Reference

| Material Type | Temperature | RH | Light | Standard |
|---------------|------------|-----|-------|----------|
| Paper/archives | 16-20°C | 45-55% | <50 lux | ISO 11799 |
| Photographs | 10-18°C | 30-40% | <50 lux | ISO 18934 |
| Film (B&W) | -5°C | 30% | dark | ISO 18911 |
| Film (color) | -20°C | 30% | dark | ISO 18911 |
| Textiles | 15-20°C | 45-55% | <50 lux | - |
| Metals | 15-25°C | <35% | varies | - |
| Digital media | 18-22°C | 35-45% | - | - |

---

## See Also

- [CIDOC-CRM v7.1.3](https://www.cidoc-crm.org/)
- [SOSA/SSN Ontology](http://www.w3.org/ns/sosa/)
- [RiC-O Ontology](https://www.ica.org/standards/RiC/ontology)
- [PREMIS v3](http://www.loc.gov/premis/rdf/v3/)
- [Getty AAT](http://vocab.getty.edu/aat/)