Note NextDNS free plan limitation

docs/dns.md

@@ -22,7 +22,6 @@ These are our favorite public DNS resolvers based on their privacy and security
 | [**Mullvad**](https://mullvad.net/en/help/dns-over-https-and-dns-over-tls) | [:octicons-link-external-24:](https://mullvad.net/en/help/no-logging-data-policy) | DoH   DoT | No[^4] | No | Based on server choice. Filter list being used can be found here. [:octicons-link-external-24:](https://github.com/mullvad/dns-adblock) | [Yes](https://mullvad.net/en/blog/profiles-to-configure-our-encrypted-dns-on-apple-devices) |
 | [**Quad9**](https://quad9.net) | [:octicons-link-external-24:](https://quad9.net/privacy/policy) | Cleartext   DoH   DoT   DNSCrypt | Some[^5] | Optional | Based on server choice, malware blocking by default. | [Yes](https://quad9.net/news/blog/ios-mobile-provisioning-profiles) |
 
-
 [^1]: AdGuard stores aggregated performance metrics of their DNS servers, namely the number of complete requests to a particular server, the number of blocked requests, and the speed of processing requests. They also keep and store the database of domains requested in within last 24 hours. "We need this information to identify and block new trackers and threats." "We also log how many times this or that tracker has been blocked. We need this information to remove outdated rules from our filters." [https://adguard.com/en/privacy/dns.html](https://adguard.com/en/privacy/dns.html)
 [^2]: Cloudflare collects and stores only the limited DNS query data that is sent to the 1.1.1.1 resolver. The 1.1.1.1 resolver service does not log personal data, and the bulk of the limited non-personally identifiable query data is stored only for 25 hours. [https://developers.cloudflare.com/1.1.1.1/privacy/public-dns-resolver/](https://developers.cloudflare.com/1.1.1.1/privacy/public-dns-resolver)
 [^3]: Control D only logs for Premium resolvers with custom DNS profiles. Free resolvers do not log data. [https://controld.com/privacy](https://controld.com/privacy)
@@ -96,7 +95,7 @@ These DNS filtering solutions offer a web dashboard where you can customize the
 
 ![NextDNS logo](assets/img/dns/nextdns.svg){ align=right }
 
-**NextDNS** is a customizable DNS service which lets you block security threats, unwanted content, and advertisements on a DNS level.
+**NextDNS** is a customizable DNS service which lets you block security threats, unwanted content, and advertisements on a DNS level. They offer a fully functional free plan for limited use.
 
 [:octicons-home-16: Homepage](https://nextdns.io){ .md-button .md-button--primary }
 [:octicons-eye-16:](https://nextdns.io/privacy){ .card-link title="Privacy Policy" }
@@ -118,6 +117,8 @@ These DNS filtering solutions offer a web dashboard where you can customize the
 
 When used with an account, NextDNS will enable insights and logging features by default (as some features require it). You can choose retention time and log storage location for any logs you choose to keep, or disable logs altogether.
 
+NextDNS's free plan is fully functional, but should not be relied upon for security or other critical filtering applications, because after 300,000 DNS queries in a month all filtering, logging, and other account-based functionality is disabled. It can still be used as a regular DNS provider after that point, so your devices will continue to function and make secure queries via DNS-over-HTTPS, just without your filter lists.
+
 NextDNS also offers public DNS-over-HTTPS service at `https://dns.nextdns.io` and DNS-over-TLS/QUIC at `dns.nextdns.io`, which are available by default in Firefox and Chromium, and subject to their default no-logging [privacy policy](https://nextdns.io/privacy).
 
 ## Encrypted DNS Proxies