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 Q1 2026 Adoption Study crawled 1,995 domains across the top 1,000 global and top 1,000 UK websites. Just 6.5% had any AI Discovery File, and 87.5% had no AI-specific policy in their robots.txt at all. The full dataset is published as open data under CC BY 4.0, with three downloadable CSVs covering adoption rates, readiness scores, and crawler blocking policies across 15 AI user agents.
The AI Visible Directory tracks verified implementations. The specifications and all research are open source on GitHub under CC BY 4.0.