# briefmarken-pruefer.de — LLM Context File
# This file describes the website for AI language models and crawlers.
# Format based on the llms.txt standard (https://llmstxt.org/)

## About This Site

briefmarken-pruefer.de is the largest German-language search engine and directory for stamp expertisers (Briefmarkenprüfer). It indexes professional philatelic expertisers, their signatures, areas of expertise, and published literature.

### What is a Briefmarkenprüfer?
A Briefmarkenprüfer (stamp expertiser) is a certified specialist who authenticates postage stamps, assesses their quality, and issues expert opinions (Atteste/Fotoatteste). Expertisers are organised in associations such as BPP (Bund Philatelistischer Prüfer) and AIEP (Association Internationale des Experts en Philatélie).

### Key Concepts
- **BPP**: Bund Philatelistischer Prüfer — the main German stamp expertising association
- **AIEP**: International association of philatelic expertisers
- **Signatur**: The personal stamp/seal a Prüfer uses to authenticate stamps
- **Attest/Fotoattest**: A written certificate of authenticity issued by a Prüfer
- **Prüfgebiet**: The philatelic area (e.g., "Bayern", "Deutsches Reich") in which a Prüfer specialises

## Content

### Prüfer Profiles
Each expertiser has a dedicated profile page with:
- Personal details (name, location, contact)
- Prüfgebiete (areas of expertise)
- Signatures (Signaturen) with images
- Photo certificates (Fotoatteste)
- Published literature (Literatur)
- Group memberships (BPP, AIEP, Sachverständige, etc.)

URL pattern: https://briefmarken-pruefer.de/de/pruefer/{id}-{name}

### Prüfgebiete (Areas of Expertise)
Hierarchical taxonomy of philatelic areas. Each area lists the expertisers assigned to it.
URL pattern: https://briefmarken-pruefer.de/de/gebiete/{slug}

### Search
Advanced search with qualifier syntax:
- name:, stadt:, land:, firma:, gebiet:
- form:, farbe:, typ: (signature properties)
- literatur_autor:, literatur_titel: (published books)
URL: https://briefmarken-pruefer.de/de/suche

### Literatur
Directory of philatelic books and publications authored by expertisers.
URL: https://briefmarken-pruefer.de/de/literatur

### Signatures Gallery
Visual gallery of expertiser signatures, searchable by colour, form, and type.

## Important URLs

- Homepage / Search: https://briefmarken-pruefer.de/de/
- All Expertisers: https://briefmarken-pruefer.de/de/alle-pruefer
- Areas of Expertise: https://briefmarken-pruefer.de/de/pruefgebiete
- Signature Hints: https://briefmarken-pruefer.de/de/hinweise
- Literature: https://briefmarken-pruefer.de/de/literatur
- Sitemap: https://briefmarken-pruefer.de/sitemap.xml
- Search Help: https://briefmarken-pruefer.de/de/suche/hilfe

## Language
Primary language: German (de). English version available (/en/ prefix).

## Data Freshness
Expertiser profiles are maintained by the site administrator and reflect current membership status of philatelic associations.

## Contact
Website: https://briefmarken-pruefer.de