> For the complete documentation index, see [llms.txt](https://sidxparab.gitbook.io/subdomain-enumeration-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sidxparab.gitbook.io/subdomain-enumeration-guide/passive-enumeration.md).

# Passive Techniques

- [Passive Sources](https://sidxparab.gitbook.io/subdomain-enumeration-guide/passive-enumeration/passive-sources.md)
- [Certificate Logs](https://sidxparab.gitbook.io/subdomain-enumeration-guide/passive-enumeration/certificate-logs.md)
- [Recursive Enumeration](https://sidxparab.gitbook.io/subdomain-enumeration-guide/passive-enumeration/recursive-enumeration.md)