120 SEO Rules
Rules Catalog Overview
Architecture of Black Sparrow's 120-rule technical SEO audit engine and scoring rubric.
Black Sparrow ships with an exhaustive catalog of 120 built-in technical SEO rules. Each rule has been meticulously designed according to modern search engine specifications (Google Search Central, RFC 9309 robots standard, W3C HTML5, and Schema.org).
Every rule includes:
- A unique rule code (e.g.
STATUS-404,CANON-002,IMG-001). - A assigned severity tier (
CRITICAL,ALERT,WARNING, orINFO). - A clear, human-friendly explanation of why it matters.
- Direct remediation steps to fix the issue.
The 13 Rule Categories
| Category | Code Prefix | Focus Area |
|---|---|---|
| HTTP & Transport | STATUS- | 404s, 5xx server errors, redirect loops, SSL/TLS certificates, TTFB. |
| Titles & Meta | META- | <title> length, duplicate titles, meta descriptions, OpenGraph. |
| Headings & Structure | H1- | Missing H1, multiple H1s, improper heading hierarchy order. |
| Directives & Robots | ROBOT- | noindex, nofollow, X-Robots-Tag, robots.txt disallows. |
| Canonicalization | CANON- | Missing canonicals, canonical loops, cross-domain mismatches. |
| Links & Anchors | LINK- | Broken internal/external links, empty anchors, generic text ("click here"). |
| Images & CWV | IMG- | Missing alt tags, missing width/height (CLS), oversized files. |
| International (Hreflang) | HREF- | Reciprocal hreflang links, missing x-default, invalid ISO codes. |
| Security Headers | SEC- | Missing HSTS, Content Security Policy (CSP), X-Frame-Options. |
| Schema & Structured Data | SCHEMA- | JSON-LD syntax, missing required fields for Google Rich Results. |
| Graph & Internal PageRank | GRAPH- | Orphan pages, click depth > 4, internal PageRank equity traps. |
| AI Search Readiness (GEO) | AI- | /llms.txt presence, AI crawler permissions (GPTBot, ClaudeBot). |
| Content & Duplication | CONT- | Near-duplicate pages (SimHash), thin content under 150 words. |
Anatomy of a Rule Finding
When Black Sparrow detects an issue, it generates a structured finding:
{
"rule_code": "CANON-002",
"category": "canonicalization",
"severity": "ALERT",
"url": "https://example.com/products/blue-shoes",
"message": "Canonical tag points to an internal page that returns HTTP 404",
"fix": "Update the rel='canonical' target URL to point to an existing, indexable 200 OK webpage."
}This structure makes it easy for developers, SEO consultants, and AI coding agents to diagnose and resolve errors rapidly.