DuckDuckGo with docs.freebsd.org finding terribly outdated documentation

From: Graham Perrin <grahamperrin_at_gmail.com>
Date: Sun, 23 Jan 2022 09:22:27 UTC
1. <https://docs.freebsd.org/en/>
2. in the search field, enter this two-word phrase:

AsciiDoc anchor

Expected:

3. relevant results

Actual result:

3. the top five results are ridiculously outdated.

What to do?

Can directories for legacy/outdated documentation be set for no
indexing and if so, is it appropriate to not index?