Custom recognizers
Custom recognizers let you configure detection rules that automatically identify and tag sensitive data during profiling and ingestion. Unlike the default auto-classification, recognizers give you full control over what patterns to detect and how to tag them.What are recognizers?
recognizers are configurable detection rules attached to classification tags. When profiling runs, recognizers analyze your data and automatically apply tags when they detect matching patterns. Each auto-applied tag includes metadata showing which recognizer detected it and the confidence score. Key benefits:- Customizable detection: Define your own patterns for organization-specific data (employee IDs, internal codes, custom formats)
- Multiple detection methods: Use regex patterns, exact terms, or 45+ pre-built detectors
- Learning from feedback: Users can report false positives, which automatically refine recognizer behavior
- Confidence-based tagging: Set minimum confidence thresholds to control precision
Recognizer types
Pattern recognizers
Use regular expressions to match structured data formats. Best for:- Emails, phone numbers, IP addresses
- Custom organizational patterns (employee IDs:
EMP-\d{5}) - Any data following predictable patterns
Exact Terms recognizers
Match specific values from a predefined list. Best for:- Known sensitive values (internal project codes, department names)
- Fixed vocabularies (country codes, status values)
- Cases requiring exact matches (no pattern variation)
Predefined recognizers
Built-in detectors from Microsoft Presidio (45+ recognizers). Best for:- Standard PII (credit cards, SSNs, passports)
- International identifiers (IBANs, UK NHS numbers, ES NIF)
- When you don’t want to write custom regex
- Financial: CreditCardRecognizer, IbanRecognizer, UsBankRecognizer
- Personal ID: UsSsnRecognizer, UsPassportRecognizer, InPanRecognizer, InAadhaarRecognizer
- Healthcare: NhsRecognizer, MedicalLicenseRecognizer
- Contact: EmailRecognizer, PhoneRecognizer, UrlRecognizer
Creating a Recognizer
- Navigate to Govern > Classification
- Select a classification (e.g., “PII”)
- Click on a tag within that classification
- Go to the recognizers tab
- Click Add Recognizer

- Configure the recognizer:
- Name: Unique identifier (e.g.,
email_pattern) - Display Name: Human-readable name (e.g., “Email Pattern Detector”)
- Description: What this recognizer detects
- Target: Choose where to analyze:
- Content: Analyze actual data values
- Column Name: Analyze only column/field names
- Confidence Threshold: Minimum score (0.0-1.0) to apply tag (default: 0.6)

- Name: Unique identifier (e.g.,
- Configure type-specific settings (see below)
- Click Submit
Pattern Recognizer Settings
- Patterns: Add one or more regex patterns, each with:
- Name: Descriptive label
- Regex: Regular expression
- Score: Confidence for this pattern (0.0-1.0)
- Context Words (optional): Words that boost confidence when found near matches (e.g., [“email”, “contact”] for email detection)
- Regex Flags: Configure case sensitivity, multi-line, etc.
Exact Terms Settings
- Exact Terms: List of exact strings to match
- Ignore Case: Whether to match case-insensitively
Predefined Recognizer Settings
- Predefined Recognizer: Select from dropdown (e.g., “UsSsnRecognizer”)
- Context Words (optional): Boost confidence with context (e.g., [“SSN”, “social security”])
- Supported Language: Select language if recognizer supports multiple
Managing recognizers
View all recognizers
The recognizers tab displays all recognizers for a tag with columns:- Enabled: Toggle to activate/deactivate
- Name & Description
- Type: Pattern, Exact Terms, Predefined, or Context
- Target: Content or Column Name
- Exceptions: Number of entities excluded from this recognizer
- Confidence: Confidence threshold
Filter & Search
Use filters to narrow the list:- Type: Pattern, Exact Terms, Predefined, Context
- Target: Content, Column Name
- Enabled: Enabled, Disabled
Edit a Recognizer
- Click Edit (pencil icon) in the Actions column
- Modify fields in the form
- Click Submit
Delete a Recognizer
- Click Delete (trash icon) in the Actions column
- Confirm deletion
Enable/Disable recognizers
Use the toggle switch in the Enabled column to temporarily stop a recognizer without deleting it. Changes take effect on the next classification run.Managing Exceptions
Click the Exceptions count to view entities where this recognizer should not run. Exceptions are automatically added when feedback is approved. You can manually delete exceptions:- Click exceptions count
- View list in the exceptions panel
- Click delete on specific exceptions
- Confirm removal
Best Practices
Creating effective recognizers
- Start with high confidence: Begin with threshold 0.7-0.8, adjust if needed
- Test patterns first: Validate regex patterns with sample data before creating the recognizer
- Use context words: Add relevant context to reduce false positives
- Multiple patterns: Create separate patterns for different formats (e.g., phone:
(123)456-7890vs123-456-7890) - Descriptive names: Use clear, searchable names and descriptions
Managing False Positives
- Review feedback regularly: Check pending feedback from users
- Adjust thresholds: If too many false positives, increase confidence threshold
- Refine patterns: Edit patterns to be more specific
- Add context words: Boost confidence for true positives with relevant context
Performance Tips
- Target appropriately: Use “Column Name” target when possible (faster than content analysis)
- Disable unused recognizers: Deactivate recognizers you no longer need
- Combine patterns: Use one recognizer with multiple patterns instead of many single-pattern recognizers
- Limit context words: Keep context word lists concise (under 20 words)
Troubleshooting
Recognizer Not Detecting Data
Check:- Recognizer is Enabled
- Confidence threshold not too high
- Pattern syntax is correct (test with a regex tool)
- Target matches your use case (Content vs Column Name)
- Entity is not in the exception list
- Profiler and auto-classification are enabled in ingestion config
Too Many False Positives
Solutions:- Increase confidence threshold
- Add context words for true positives
- Make patterns more specific
- Consider using exact terms recognizer instead
- Let users submit feedback to build exception lists
Pattern Not Matching
Common issues:- Missing escape characters in regex (use
\\dnot\d) - Incorrect regex flags (check case sensitivity, multi-line)
- Pattern too specific or too broad
- Test your pattern at regex101.com first
Next Steps
Tag Feedback & Approval
Learn how to report false positives and improve recognizer accuracy through user feedback
Auto PII Tagging
Understand the default PII tagging logic