Allowed in public:

• General concepts (what a homelab is, why self-host)
• Sanitized architecture diagrams (no live IPs or hostnames)
• Links to public services (status page, landing site)
• Learning-oriented material safe for anyone on the internet

Never in public:

• Live IP addresses, CTIDs, internal hostnames
• Credentials, API tokens, recovery codes
• Incident details, security findings, or admin runbooks
• Anything you would not paste on a public blog post