Restricted Content Filtering

How Restricted Content Is Classified

Restricted content is a configurable policy bucket for material that is legal but commonly age-gated or governed by acceptable-use rules — mature themes, sensitive subject matter, and content that individual organizations choose to control based on their environment. Rather than a single fixed definition, it functions as a flexible layer administrators tune to their own internet-safety policy.

The engine classifies candidate domains using the same multi-signal methodology as the rest of the taxonomy — content analysis, commerce and intent detection, reputation, and metadata — and exposes the result as a distinct category so it can be enforced, relaxed, or combined with others without disturbing more sharply defined categories such as adult content or violence.

Because restricted content spans a range of sensitivity, configurability is the point. A K-12 network enforces it strictly; a higher-education or corporate network may relax it. Continuous re-scanning keeps the category current, and every classification carries a confidence score so policy engines can set their own thresholds.

Deployment Options

DNS-based filtering applies the restricted-content layer network-wide with minimal setup: point resolvers at the API or load the RPZ feed to protect every device, capturing requests from all applications.

Web-proxy integration through ICAP or ECAP adds inline inspection for HTTPS traffic under SSL inspection, useful where restricted material appears on shared platforms whose parent domain is not classified.

Developers and MSPs can call the real-time API for sub-10ms lookups with confidence scores, setting per-customer thresholds and combining restricted content with other categories in their policy engine.

• DNS RPZ feeds updated every 15 minutes
• ICAP/ECAP support for web proxy integration
• REST API with sub-10ms response times
• SDKs for Python, Node.js, Go, Java, and C#

// Check restricted content classification
curl -X GET "https://api.webfilteringdb.com/v1/lookup" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{"domain": "example-domain.com"}'

// Response
{
  "domain": "example-domain.com",
  "categories": ["restricted_content"],
  "subcategory": "age_gated",
  "confidence": 0.98,
  "action": "block"
}

# BIND RPZ configuration for restricted content blocking
zone "rpz.webfilteringdb.com" {
    type slave;
    masters { 198.51.100.1; };
    file "rpz-restricted_content.db";
};

# Response policy zone applied to all queries
options {
    response-policy {
        zone "rpz.webfilteringdb.com"
            policy nxdomain;
    };
};