P3P: policyref="https://www.googleadservices.com/pagead/p3p.xml", CP="NOI DEV PSA PSD IVA IVD OTP OUR OTR IND OTC"

Largely abandoned format for declaring website's privacy policy in machine-readable format. The only reason for many websites to use the header was that old versions of Microsoft Internet Explorer disallowed third-party cookies on websites missing P3P.

Location: https://www.google.co.uk/ads/ga-audiences?v=1&aip=1&t=sr&_r=4&tid=UA-109011373-1&cid=539709513.1601991251&jid=1029425060&_v=5.7.2&z=164822894&slf_rd=1&random=2903273980

The HTTP Location header is being returned by a server to redirect the web browser to a new URL of the requested resource. The URL may be relative (/index.html) or absolute (https://example.com).

X-Content-Type-Options: nosniff

A non-standard but widely accepted header introduced originally by Microsoft to disable "content sniffing" or heuristic content type discovery in absence or mismatch of a proper HTTP Content-Type declaration, which led to a number of web attacks. In general, presence of the header with its only defined value of nosniff is considered as part of a properly secured HTTP response.

Server: cafe

Announces web server software and optionally version details.

X-XSS-Protection: 0

Controls an Cross-Site Scripting (XSS) filters built into the majority of web browsers. The filter is usually turned on by default anyway, but requirement to set the header to 1 became part of canonical set of "secure" HTTP headers. Over time, vulnerabilities in the "sanitizing" mode filter were found, so 1; mode=block became the recommended value. Some companies decided that they don't really need a browser-side XSS filter to mess with their web services which are XSS-free anyway and they became consciously disabling the XSS filter by setting the header to 0.