RFC 10023 adds a simple, machine-readable “for sale” signal to the DNS.

You search for a domain name and discover that it is already registered. From the perspective of most domain search tools, that is usually the end of the story: unavailable.

But that may not be true.

The domain may be parked, unused, held by a domain investor—or its owner may simply be willing to sell it.

So there are really two different questions:
Is this domain name registered?

And:
Is this domain name available for purchase?

DNS, WHOIS and RDAP are good at answering the first question. Until recently, there was no simple, standardized way to signal the second.

RFC 10023 aims to fill that small but useful gap.

A digital “For Sale” sign

The idea is deliberately simple. A domain holder can publish a TXT record at a reserved DNS node:

_for-sale.example.com. IN TXT “v=FORSALE1;”

That’s it.

The _for-sale node acts as a digital “For Sale” sign attached to the domain name. The domain continues to operate normally, and the owner can add or remove the signal whenever they choose.

The record can also contain additional information, such as a URI pointing to a sales page or an indicative asking price:

_for-sale.example.com. IN TXT "v=FORSALE1;furi=https://example.com/sale"

_for-sale.example.com. IN TXT "v=FORSALE1;fval=EUR5000"

The important part, however, is not the TXT syntax. It is the signal.

From “Taken” to “Registered—For Sale”

Consider a domain search application checking three names:

example.com - registered example.net—available example.org - registered

With RFC 10023, the first result could instead be:

example.com - registered, for sale example.net - available example.org - registered

That is a much more useful representation of reality.

And because the signal is in DNS, any application can consume it. A registrar could incorporate it into its search interface. A marketplace could automatically discover owner-published inventory. A broker could monitor domains whose holders have explicitly indicated that they want to sell. A search engine could include registered-but-for-sale domains in its results.

The signal is attached to the domain itself. The owner does not have to choose a particular intermediary to make it discoverable.

DNS is not the marketplace

This distinction is important.

RFC 10023 does not define how domain names are bought or sold. It does not define auctions, escrow, authentication of offers, brokers, marketplaces or domain transfers.

It simply provides a standardized way to say:

“This registered domain is available for purchase.”

The actual transaction remains outside DNS.

That keeps the convention small and broadly applicable. A registry may use its own code to connect the signal to a controlled sales page. An owner may publish a URI directly. An application may simply use the presence of the record as another piece of information about the domain.

There is no central database to synchronize, no new protocol or port, and no requirement to park the domain or take its existing website offline.

A missing bit of information

The domain aftermarket already exists. Domains are bought, sold and brokered every day.

What is often missing is a universally recognizable signal attached to the domain itself.

A domain can be registered, unused, valuable and available for purchase, while an automated system simply reports “Taken”.

That is a surprisingly lossy representation of reality.

RFC 10023 adds a small but useful piece of information:

Registered – but for sale.

It also gives domain holders another option. Instead of simply letting an unwanted domain expire, they can explicitly signal that they are willing to sell it while they still control it.

This does not replace marketplaces, brokers or domain investors. Nor is it intended to regulate the domain aftermarket. It simply makes an existing fact about a domain machine-readable.

Sometimes all you need is a sign

One of the appealing things about RFC 10023 is how little it tries to do.

It does not turn DNS into a marketplace. It does not create a new business model. It does not pick a particular commercial intermediary.

It simply adds a small piece of information to a system that is already globally distributed and widely queried.

The domain is registered.

The DNS says it is for sale.

Now the Internet can know the difference.

Sometimes the most useful additions to the DNS are not the complicated ones.

Sometimes all you need is a sign.