Use Cases

Fresh

Practical examples and applications across different domains. All examples are complete, working MD-LD documents.

Personal Knowledge Management

Journal Entries

[my] <tag:alice.smith@example.org,2026:>
[j]  <my:journal/>

# 2026-05-06 {=j:2026-05-06 .j:Entry j:date ^^xsd:date}

## A good walk {label}

Mood: [happy] {j:mood}
Energy: [8] {j:energy ^^xsd:integer}

Met [Bob] {+my:bob ?j:met} at [Central Park] {+my:central-park ?j:location}.
The weather was [sunny] {j:weather}.

Generated quads track: date, mood, energy, who was met, location, weather. Historical queries are just array filters.

Project Tracking

[my] <tag:you@example.com,2026:>

# Project Alpha {=my:alpha .my:Project label}

Status: [active] {my:status}
Priority: [high] {my:priority}

Tasks: [design] {+#design ?my:task sh:name}, [build] {+#build ?my:task sh:name}.

## Design {=#design .my:Task label}
[done] {my:status}
Completed: [2026-04-15] {my:completedDate ^^xsd:date}

## Build {=#build .my:Task label}
[in-progress] {my:status}

Learning Logs

[my] <tag:you@example.com,2026:>
[l] <my:learning/>

# Understanding RDF {=l:rdf-basics .l:Topic label}

Date: [2026-05-06] {l:studiedOn ^^xsd:date}
Source: [Semantic Web Primer] {l:source}
Confidence: [7] {l:confidence ^^xsd:integer}

Key concepts:
- Triples {+#triples ?l:concept label}
- Named graphs {+#named-graphs ?l:concept label}

Developer Documentation

API Endpoints

[api] <tag:brian@example.org,2026:app/api/>

# Get User by ID {=api:/users/:id .api:Endpoint label}

Method: [GET] {+api:methods/GET ?api:method}
Path: [/users/:id] {api:path}
Status: [200 OK] {api:status}
Auth: [required] {api:auth}

Returns user by their unique identifier.

Schema Documentation

[schema] <tag:you@example.com,2026:schema/>

## User {=schema:User .rdfs:Class label}

> A registered user of the application. {comment}

Properties:
- id {+schema:id ?schema:property sh:name}
- email {+schema:email ?schema:property sh:name}
- name {+schema:name ?schema:property sh:name}

### User.id {=schema:id .rdf:Property label}
Range: [xsd:string] {+xsd:string ?rdfs:range}
> Unique identifier. {comment}

### User.email {=schema:email .rdf:Property label}
Range: [xsd:string] {+xsd:string ?rdfs:range}
> Email address. {comment}

Architecture Diagrams

[arch] <tag:you@example.com,2026:architecture/>

# API Gateway {=arch:gateway .arch:Component label}

Handles all inbound requests:
- Auth service {+arch:auth ?arch:dependsOn label}
- User service {+arch:users ?arch:dependsOn label}
- Analytics {+arch:analytics ?arch:dependsOn label}

## Auth Service {=arch:auth .arch:Component label}
Port: [8080] {arch:port ^^xsd:integer}
Tech: [Node.js] {arch:technology}

Academic Research

Research Paper with Citations

[alice] <tag:alice@example.org,2026:>

# Semantic Web {=alice:research/paper-semantic-markdown .alice:ScholarlyArticle label}

Is part of [semantic research] {+alice:research/semantic !member}

Authored by [Alice Johnson] {+alice:alice-johnson ?alice:author} on [2026-08-12] {alice:datePublished ^^xsd:date}.

Cites [Berners-Lee 2001] {+alice:ref-berners-lee ?alice:cites label}.

Experiment Tracking

[exp] <tag:lab@example.org,2026:experiments/>

## Experiment 47 {=exp:e47 .prov:Activity label}

Started: [2026-05-01T09:00:00Z] {prov:startedAtTime ^^xsd:dateTime}
Ended:   [2026-05-01T11:30:00Z] {prov:endedAtTime ^^xsd:dateTime}

Run by: [Dr. Chen] {+exp:chen ?prov:wasAssociatedWith}
Used: [Dataset v3.2] {+exp:dataset-v3-2 ?prov:used}
Produced: [Results 47a] {+exp:results-47a ?prov:generated}

Hypothesis: [confirmed] {exp:outcome}
P-value: [0.003] {exp:pValue ^^xsd:decimal}

Dataset Documentation with Provenance

[data] <tag:you@example.com,2026:datasets/>

# Medical Imaging Dataset {=data:med-img-v2 .prov:Entity label}

Version: [2.0] {data:version}
Records: [50000] {data:recordCount ^^xsd:integer}
Format: [DICOM] {data:format}

Derived from [v1 dataset] {+data:med-img-v1 ?prov:wasDerivedFrom}.
Created by [Lab pipeline v3] {+data:pipeline-v3 ?prov:wasGeneratedBy}.

Content Management

Blog Post

[blog] <tag:justin@example.org,2026:>

# Understanding MD-LD {=blog:post-mdld .blog:Post label}

Published: [2026-05-10] {blog:datePublished ^^xsd:date}
Author: [Justin] {+blog:justin ?blog:author label}
Tags: [rdf] {+blog:tag/rdf ?blog:tag label}, [markdown] {+blog:tag/md ?blog:tag label}

[MD-LD] {blog:emphasized} allows you to embed RDF directly in Markdown.

Product Catalog

[prod] <tag:shop@example.com,2026:>

## Widget Pro {=prod:widget-pro .prod:Product label}

Price: [49.99] {prod:price ^^xsd:decimal}
SKU: [WGT-PRO-001] {prod:sku}
In stock: [true] {prod:inStock ^^xsd:boolean}
Category: [Tools] {+prod:category/tools ?prod:category label}

Data Integration

Database Schema Documentation

[db] <tag:you@example.com,2026:schema/>

## Users Table {=db:users .db:Table label}

Columns:
- id {+#id ?db:column .db:Column label}
- email {+#email ?db:column .db:Column label}
- created_at {+#created ?db:column .db:Column label}

### id {=#id .db:Column label}
Type: [UUID] {+db:type/uuid ?db:type}
Primary key: [true] {db:isPrimaryKey ^^xsd:boolean}

ETL Workflow Documentation

[etl] <tag:data@example.com,2026:workflows/>

## Customer Import {=etl:customer-import .prov:Activity label}

Source: [CRM export] {+etl:crm-export ?prov:used label}
Target: [Data warehouse] {+etl:warehouse ?prov:generated label}

Steps:
- Extract {+#extract ?etl:step sh:name}
- Transform {+#transform ?etl:step sh:name}
- Load {+#load ?etl:step sh:name}

Business Processes

Invoice Processing

[biz] <tag:company@example.com,2026:finance/>

## Invoice INV-2026-042 {=biz:inv-2026-042 .biz:Invoice label}

Amount: [4500.00] {biz:amount ^^xsd:decimal}
Currency: [USD] {biz:currency}
Due: [2026-06-15] {biz:dueDate ^^xsd:date}

From: [ACME Supplies] {+biz:acme ?biz:vendor label}
Approved by: [Alice Manager] {+biz:alice ?biz:approver label}
Status: [approved] {biz:status}

Approval Workflow

[proc] <tag:company@example.com,2026:approvals/>

## PR #42 Approval {=proc:pr-42-approval .proc:Approval label}

Requested by: [Bob Dev] {+proc:bob ?proc:requestedBy}
Requested: [2026-05-06T14:00:00Z] {proc:requestedAt ^^xsd:dateTime}
Status: [pending] {proc:status}

Approvers:
- [Alice Manager] {+proc:alice ?proc:requires label}
- [Carol Tech Lead] {+proc:carol ?proc:requires label}

Approved by: [Alice Manager] {+proc:alice ?proc:approvedBy}
Approved: [2026-05-07T10:30:00Z] {proc:approvedAt ^^xsd:dateTime}

LLM Agent Memory

MD-LD serves as an ideal memory substrate for LLM agents — plain text that is parseable, mergeable, and diffable:

[agent] <tag:agent-memory@example.com,2026:>

# Session 2026-05-06 {=agent:session-2026-05-06 .prov:Activity label}

## Alice Thompson {=agent:alice .prov:Person label}

[Prefers concise responses] {agent:preference}
[Senior engineer] {agent:role}
[Python, TypeScript] {agent:skills}
Mentioned [project X is behind schedule] {+agent:project-x-status ?agent:mentioned}

## Context Notes {label}

[Discussed API redesign for 45 minutes] {agent:sessionNote}
[Agreed to follow up on Friday] {agent:followUp}

Parse at session start, merge new observations, generate updated memory file. No database required.