A domain can now say it is for sale, in DNS

The _for-sale DNS leaf node name, defined by RFC 10023, allows domain owners to indicate that a specific domain is available for purchase without disrupting the site's functionality or altering the WHOIS and RDAP information. A TXT record published at _for-sale.example.com signals to potential buyers that the domain is negotiable, while maintaining the live site, email, and mail services.

The purpose of this convention is to provide a channel for domains that have never had an explicit sale signal, enabling interested buyers to learn about the opportunity directly. This method of signaling a domain's availability through DNS is useful for brokers and automated availability services, as it offers an additional lookup option that a website's homepage cannot convey.

By including the record in the DNS zone file, the risk to the site is minimal, as browsers do not display the _for-sale record. To ensure authenticity, it is recommended to sign the zone with DNSSEC when publishing the _for-sale record.