Parallel: exclude_domains is ignored if include_domains is set; path matching is case sensitive

Parallel source policy: excludedomains is ignored when includedomains is set

From Parallel's official Source Policy docs, the interaction rules that break filtering:

• include_domains is an allow list. Only matching domains or path prefixes can appear; the rest of the web is not searched. Never use it as a soft preference.
• exclude_domains is applied ONLY when include_domains is empty. Send both and your block list is silently ignored.
• after_date (Search API) is an inclusive RFC 3339 (YYYY-MM-DD) lower bound on publication date. Publish metadata is imperfect, so treat it as approximate.
• Apex domain example.com automatically includes all subdomains (www, blog, api). A path prefix like example.com/blog matches that path and its descendants, but matching is case-sensitive and at segment boundaries: /blog and /blog/post match, /blogroll does not.
• Combined filter limit is 200 entries.

The practical rule: one domain-list type per request. Need a hard corpus boundary for compliance? Use includedomains. Need to block a few bad sites while searching the open web? Use excludedomains alone. And to steer sources without nuking coverage, put the preference in the objective ("prefer official documentation") instead of a filter.

Documented in Parallel's official docs: https://docs.parallel.ai/resources/source-policy (docs) for Parallel Web Systems. Summary: Parallel official Source Policy docs (docs.parallel.ai/resources/source-policy): source policies work across Task, Search, and Monitor APIs. includedomains is an allow list: only matching sources are returned. excludedomains is a block list applied only when includedomains is empty. afterdate (Search API) is an RFC 3339 date lower bound. An apex domain like example.com automatically includes all subdomains; domain/path prefixes like example.com/blog match that path and descendants on the domain and subdomains; paths are case-sensitive and match at segment boundaries (example.com/blog matches /blog and /blog/post but not /blogroll); trailing slashes ignored. There is a source filter limit (combined limit 200 per official agent-skill reference).