Czech Document Anonymization

Protect sensitive data before sending it to LLMs or third parties. This skill handles the redaction of Czech personal identifiers, names, and locations using a deterministic placeholder system. It solves the risk of leaking PII (Personally Identifiable Information) in documents like court rulings, medical reports, and bank statements while maintaining the document's internal logic and readability.

What it does

• PII Redaction replaces names, addresses, and organizations with consistent placeholders like OSOBA1 or MESTO1.
• Checksum Verification runs secondary offline checks for birth numbers (rodné číslo), IČO, IBAN, and credit card numbers using mathematical validation.
• Multi-language Support identifies entities in Czech plus 30 other languages using LINDAT NLP services.
• Context Preservation keeps clinical codes (ICD-10) and statute citations intact to ensure the document remains useful for analysis.
• Morphological Analysis extracts lemmas and parts of speech to help understand document structure without exposing identities.

How it works

1. Selection of the anonymization mode, choosing between the default API or the Zero-egress offline mode for highly sensitive data.
2. Execution of the anonymize command to generate deterministic placeholders across the entire text.
3. Verification using the bundled pii_leak_check.py script to find surviving identifiers via regex and checksums.
4. Validation through extract_entities to confirm no remaining personal names or specific locations exist.

Frameworks & tools

This skill utilizes the anonymize-mcp server, LINDAT NLP tools (NameTag, UDPipe), and a specialized Python verification script.

Why this beats prompting it yourself

Standard LLM prompts often hallucinate PII or miss identifiers hidden in complex Czech grammar. This skill uses deterministic NLP models and mathematical checksums to ensure that birth numbers and bank accounts are actually validated, not just guessed at.

Use cases

• Redacting medical reports before generating an AI summary.
• Preparing court rulings for public disclosure by removing names and dates.
• Scrubbing bank statements of account numbers and IBANs for financial analysis.
• Cleaning HR documents before sharing them with external recruiters.

Known limitations

Non-commercial use only due to CC BY-NC-SA model licenses. Offline mode disables translation and readability tools to prevent data egress. Requires local installation of anonymize-mcp.