A domain can now signal it is for sale using a reserved DNS leaf node name defined by RFC 10023 and registered with IANA. A TXT record at _for-sale.example.com indicates that example.com is available for purchase. The record carries a mandatory version tag followed by at most one tag=value pair, such as ftxt=Free, furi=mailto:[email protected], or fval=EUR2500.00.

The signal sits beside a live site in DNS and says nothing to a browser, ensuring the homepage keeps serving and the mail keeps flowing. It is not the same as registration data; WHOIS and RDAP answer whether a name is registered, but a registered name may still be purchasable. The convention exists because there is no channel for domain owners to notify interested buyers.

Brokers and automated availability services are the intended audience. The signal is externally checkable, costs one record, and carries no risk to the site itself. The version tag is mandatory and case-sensitive.

One tag-value pair per record is required. The TTL should be 3600 seconds or less. The convention has no "not for sale" value; absence is the only way to say no.

Sign the zone with DNSSEC if you can. An unsigned TXT record asserting your domain is for sale is easily forgeable. Common mistakes include cramming several pairs into one record, publishing it aspirationally, and trusting the content.

If you are on the reading side, ftxt= is attacker-controlled text and furi= is an attacker-controlled URI, so sanitize before display. The record resolves at all, but during a redemption or pending Delete period, or when DNSSEC validation is bogus, the name will not resolve and the signal silently disappears.