RFC 10023 is an Informational publication published in July 2026 by the IETF ('The _for-sale Underscored and Globally Scoped DNS Node Name'), authored by Marco Davids (SIDN Labs). It defines a machine-readable convention in the DNS for domain owners to publish availability for sale via _for-sale TXT records.

What is the designated DNS node for RFC 10023?

The standardized DNS node is '_for-sale.[domain]', such as '_for-sale.example.com'. A TXT record is placed there starting mandatory with 'v=FORSALE1;'.

Which registries already support RFC 10023?

The Dutch ccTLD registry SIDN (.nl) natively evaluates RFC 10023 during Whois and domain availability searches. The standard is also supported across various registrars, developer tools, and scanners.

How do registrars and brokers discover that a domain is for sale?

Registrars like SIDN for .nl perform a DNS query for Type 16 (TXT) at the node name _for-sale during domain availability checks. When the resolver finds "v=FORSALE1", the registrar immediately presents the asking price and contact URI to the buyer.

What are the costs of using RFC 10023?

None. RFC 10023 is a freely usable IETF specification (Category: Informational). DNS TXT records are included at zero additional cost with virtually every domain registrar and hoster.

How do domain owners protect themselves from email spam?

In the furi tag, we strongly recommend pointing to a protected contact form, a project landing page, or an escrow service (e.g. Escrow.com) rather than exposing a plain mailto: address. This preserves full machine-readability while blocking spam harvesters.

What is the purpose of the mandatory v=FORSALE1 tag?

v=FORSALE1 is the standardized protocol and version header specified by RFC 10023. It must appear at the start of every RFC 10023 TXT record followed by a semicolon. Without this tag, automated parsers and registrars will ignore and discard the record.

Which currency and pricing formats are supported in fval?

The fval tag strictly requires the 3-letter ISO 4217 currency code immediately prefixed to the numerical value without spaces (e.g. EUR5000 or USD12500). Decimals are separated by a period (e.g. EUR2500.50). For negotiable pricing (OBO), the fval tag is omitted and clarified in the ftxt field.

How does RFC 10023 integrate with DNSSEC?

RFC 10023 works seamlessly with DNSSEC. Since _for-sale is a standard node within the DNS zone, the TXT RRset is cryptographically signed by the corresponding RRSIG record. This guarantees tamper-proof validation for buyers and registrars against DNS spoofing and cache poisoning attacks.

What Time-to-Live (TTL) should be configured for the TXT record?

RFC 10023 (§ 3.4) recommends a TTL of 3600 seconds (1 hour) or less, and all records in the RRset should share the same TTL. If pricing changes or the domain is sold, the change then reaches resolver caches within an hour. This is often overlooked in practice: according to the ForSaleDNS study (August 2026), about a third of all records use a TTL above 3600 seconds. Our validator flags this.

Is a DNS sale record a legally binding offer to contract?

No. Under international civil and contract law, publishing an asking price in a DNS record constitutes an invitation to treat (invitatio ad offerendum). Domain owners retain full contractual liberty to accept or reject incoming acquisition bids.

Do legal imprint and disclosure laws apply to the DNS record?

A DNS TXT record itself is not a telemedia service and cannot house a complete imprint due to byte limits. However, the contact URI specified in furi must lead to a site containing complete imprint and privacy disclosure notices.

What if my registrar or DNS control panel forbids underscores in hostnames?

Some legacy web panels mistakenly validate DNS leaf nodes against archaic hostname syntax (RFC 1123). In such cases, you can delegate nameservers free of charge to modern DNS providers like Cloudflare, Hetzner DNS, or deSEC while retaining your domain registration.

Is there a character or byte limit for the TXT record?

Yes. RFC 10023 (§ 2.4) requires each _for-sale TXT record to consist of exactly one character-string of at most 255 bytes. Longer records split into several strings (e.g. "v=FORSALE1;" "ftxt=…") are non-conformant – multiple pieces of information belong in separate TXT records. Our generator tracks the limit in real time (Byte-Guard), and the validator detects split records.

Can a domain remain live with an active website while signaling sale availability?

Yes! This is one of RFC 10023’s premier advantages. Your live web application, store, or blog on www and the apex domain functions without interruption. Only the dedicated _for-sale node signals availability to prospective buyers and registrars in the background.

Who already supports RFC 10023?

RFC 10023 is already evaluated, documented, or natively published via authoritative nameservers across registries (SIDN Labs), marketplaces (Atom with automated nameserver rollout), domain intelligence platforms, scanners, and developer tools. See our continuously updated directory in the Ecosystem & Adoption section.

How widely adopted is RFC 10023?

Adoption can only be approximated because different scanners utilize distinct data sources and scanning methodologies. rfc10023.de documents verified metrics and historical telemetry transparently in the Adoption Tracker.

Where can I find current RFC 10023 integrations?

A categorized directory of verified integrations, tools, scanners, and documentation is maintained in the RFC 10023 Ecosystem & Adoption Tracker.

What security risks come with the _for-sale record?

Any domain holder can put arbitrary content into a DNS record. RFC 10023 (§ 5) therefore points out: furi links may lead to phishing pages and must never be followed automatically; content must be escaped before display (protection against XSS and Unicode tricks such as homographs); mailto and tel values can be harvested by scrapers; the price is non-binding. Our validator displays content escaped only, opens links on click only and warns about mixed-script domains. Additional protection against tampering: DNSSEC.

What happens if my zone has a wildcard TXT record?

A wildcard such as *.example.com also answers for _for-sale.example.com if no explicit record exists there. If the wildcard TXT happens to contain "v=FORSALE1;", the domain appears to be for sale. RFC 10023 (§ 2.5) clarifies that wildcards only work as leaf names; constructs like _for-sale.*.example are invalid. Our validator additionally queries a random sibling name and warns if it returns the same answer.

Frequently Asked Questions

Common Questions about RFC 10023

Detailed answers to the most critical technical, legal, and operational questions regarding the IETF Informational publication RFC 10023 for domain sale signals in the DNS.

Traditional domain parking substitutes original website content with third-party advertising links. With RFC 10023, your domain stays on your regular nameservers and existing web content remains intact. The sale intent is published as a dedicated TXT record at the _for-sale node, accessible to registrars and prospective buyers without altering your main website.

According to RFC 10023 Section 2.1, the IETF specification states that each TXT record should contain exactly one tag-value pair (e.g. record 1 with "v=FORSALE1;fval=USD195000" and record 2 with "v=FORSALE1;furi=https://..."). Our generator supports both this multi-line standard and a single-line fallback for limited DNS control panels.

Test a Domain Live

Check _for-sale TXT records & DNSSEC

Build Record with Byte-Guard

Exports for Cloudflare, Hetzner, BIND

Citation Reference for Publications & Media

RFC 10023 Editorial Board (2026). RFC 10023 FAQ & Technical Guide. rfc10023.de. Retrieved on September 25, 2026, from https://www.rfc10023.de/en/faq

Published: October 2026 · IETF Informational RFC