Creator & Maintainer
AI Visibility Definition
Mark created the AI Visibility Definition: the degree to which a website can be discovered, interpreted, and cited by AI systems. The accompanying AI Discovery File Specifications define 10 machine-readable files (including llms.txt, ai.json, identity.json, and brand.txt) across three implementation tiers.
The Q2 2026 Adoption Study crawled 1,905 domains across the top 1,000 global and top 1,000 UK websites. Just 7.2% had any AI Discovery File (up from 6.5% in Q1), and 85% had no AI-specific policy in their robots.txt. The llms.txt file saw the strongest growth, nearly doubling from 35 to 61 valid implementations. All datasets are published as open data under CC BY 4.0, tracking adoption rates, readiness scores, and crawler blocking policies across 15 AI user agents.
For WordPress sites, Mark built the AI Discovery Files plugin, which generates all 10 files directly from the WordPress admin with auto-detection, live preview, and validation. No coding needed.
The AI Visible Directory tracks verified implementations. The specifications and all research are open source on GitHub under CC BY 4.0.