Always ensure external URLs use HTTPS when available and verify that links resolve correctly before including them in documentation or code. HTTP links expose users to potential security risks through unencrypted connections, while broken or incorrect URLs create poor user experience and may indicate outdated dependencies.

When adding external links:

  1. Prefer HTTPS over HTTP for security (e.g., use https://bit.ly/go-slack-signup instead of http://bit.ly/go-slack-signup)
  2. Test that URLs actually resolve to the intended resource
  3. For repository links, verify the correct path (e.g., https://github.com/anacrolix/torrent/tree/master/dht for source code or https://godoc.org/github.com/anacrolix/torrent/dht for documentation)

This practice protects users from security vulnerabilities and ensures reliable access to referenced resources.