**Extraction from the pinax.json metadata file**

@file_pinax:document {type: "metadata", format: "PINAX"}  

@file_pinax -> describes -> @test_2_collection  

@test_2_collection -> created -> @date_2017  
@test_2_collection -> language -> "en"  
@test_2_collection -> description -> "A collection of various posts, datasets, and metadata files including tutorials, announcements, historical essays, and system files from the Arke Institute digital collection."  
@test_2_collection -> rights -> "Copyright Substack, Unknown"  
@test_2_collection -> source -> "PINAX"  

**Creators (already defined in subdirectory, referenced here)**  

@substack -> creator_of -> @test_2_collection  
@nchimicles -> creator_of -> @test_2_collection  
@arke_institute -> creator_of -> @test_2_collection  

**Institution**  

@test_2 -> institution_of -> @test_2_collection  

**Places (common‑knowledge entities – referenced)**  

@test_2_collection -> place -> [@europe, @florence, @bruges, @paris, @spain, @jerusalem, @rome, @germany]  

**Subjects – defined as concepts (new entities)**  

@substack:concept {description: "The Substack publishing platform"}  
@editor_tutorial:concept {description: "Tutorials for using the Substack editor"}  
@announcements:concept {description: "Official announcements posted on Substack"}  
@subscriptions:concept {description: "Subscription mechanisms for Substack newsletters"}  
@newsletter:concept {description: "Newsletter publications distributed via Substack"}  
@medieval_europe:concept {description: "Historical period covering Europe in the Middle Ages"}  
@catholic_church:concept {description: "The Roman Catholic Church"}  
@indulgence_system:concept {description: "Medieval Catholic practice of granting indulgences"}  
@wealth_inequality:concept {description: "Economic disparity between social classes"}  
@social_hierarchy:concept {description: "Structured ranking of individuals within a society"}  
@christianity:concept {description: "Christian religious tradition"}  
@historical_analysis:concept {description: "Scholarly examination of past events"}  
@economic_history:concept {description: "Study of economic developments over time"}  
@religious_history:concept {description: "Study of the evolution of religious beliefs and institutions"}  
@social_critique:concept {description: "Critical examination of social structures"}  
@metadata:concept {description: "Data that describes other data"}  
@system_files:concept {description: "Files that support system operation and preservation"}  
@digital_preservation:concept {description: "Practices aimed at preserving digital objects over time"}  

**Linking the collection to its subjects (synthesis across sub‑directories)**  

@test_2_collection -> subject -> @substack  
@test_2_collection -> subject -> @editor_tutorial  
@test_2_collection -> subject -> @announcements  
@test_2_collection -> subject -> @subscriptions  
@test_2_collection -> subject -> @newsletter  
@test_2_collection -> subject -> @medieval_europe  
@test_2_collection -> subject -> @catholic_church  
@test_2_collection -> subject -> @indulgence_system  
@test_2_collection -> subject -> @wealth_inequality  
@test_2_collection -> subject -> @social_hierarchy  
@test_2_collection -> subject -> @christianity  
@test_2_collection -> subject -> @historical_analysis  
@test_2_collection -> subject -> @economic_history  
@test_2_collection -> subject -> @religious_history  
@test_2_collection -> subject -> @social_critique  
@test_2_collection -> subject -> @newsletters          {ref: @newsletters:concept}  
@test_2_collection -> subject -> @email_marketing      {ref: @email_marketing:concept}  
@test_2_collection -> subject -> @content_management   {ref: @content_management:concept}  
@test_2_collection -> subject -> @metadata  
@test_2_collection -> subject -> @system_files  
@test_2_collection -> subject -> @digital_preservation  

**File‑level subject and place tagging (extracted from the JSON arrays)**  

@file_pinax -> has subject -> [  
  @substack, @editor_tutorial, @announcements, @subscriptions, @newsletter,  
  @medieval_europe, @catholic_church, @indulgence_system, @wealth_inequality,  
  @social_hierarchy, @christianity, @historical_analysis, @economic_history,  
  @religious_history, @social_critique, @newsletters, @email_marketing,  
  @content_management, @metadata, @system_files, @digital_preservation  
]  

@file_pinax -> has place -> [@europe, @florence, @bruges, @paris, @spain, @jerusalem, @rome, @germany]  

**Synthesis – connecting entities across sub‑directories**

- The **creators** (@substack, @nchimicles, @arke_institute) appear both as *metadata creators* (via the PINAX file) and as *platform hosts* for the underlying Substack posts (see the *posts* sub‑directory).  

- All **subjects** listed for the collection are shared with the *posts* and *newsletter_posts* sub‑directories, establishing a thematic bridge: the Substack platform, medieval‑European religious/economic analysis, and digital‑preservation concerns.  

- The **places** associated with the collection (European cities and regions) are also referenced in the *historical analysis* documents of the *posts* sub‑directory, linking geographic context to content.  

- The **newsletter‑posts dataset** (from the *newsletter_posts* sub‑directory) contains the same individual documents that are referenced in the *posts* sub‑directory (e.g., @post_125962878_coming_soon ↔ @coming_soon_announcements), illustrating material overlap across collections.  

- The **system‑files metadata** (e.g., @file_pinax) ties together the technical preservation layer with the scholarly content, reinforcing the collection’s dual focus on *content* and *digital stewardship*.  

---  

**Overall picture**

The **Test‑2 Collection** (@test_2_collection) aggregates:

1. **Content** – Substack tutorials, announcements, and historical essays (from the *posts* sub‑directory).  
2. **Newsletter data** – Structured dataset of newsletter posts and their source documents (from the *newsletter_posts* sub‑directory).  
3. **Technical assets** – Metadata and system files supporting digital preservation (from the *system_files* sub‑directory).  

These three strands converge on a shared set of **subjects**, **places**, and **creators**, forming a cohesive, cross‑source knowledge graph that captures both the scholarly themes and the infrastructural context of the collection.