DNS Providers & Hosters Compatibility Matrix
Which DNS hoster supports underscore labels like _for-sale in their web interface? Detailed test results for Hetzner, Cloudflare, INWX, Netcup, Strato, IONOS and more.
DNS Zone Editors & Providers RFC 10023 Benchmark
Compatibility details are based on documented hands-on tests, official provider sources, or verified technical notices. DNS interfaces and validation rules may change over time. Consequently, the date of last verification is displayed for every provider.
| Provider & Region | Status & Verification | Zone Editor Syntax | Practical Notes |
|---|---|---|---|
Hetzner DNS ConsoleGermany | Verified supported Hands-on test Verified: Sep 28, 2026· Hands-on test: Sep 28, 2026 | Name: _for-sale | Typ: TXT | Wert: v=FORSALE1;fval=EUR2500 | Hetzner supports leading underscores (RFC 8552) without warning in both the web console and DNS API. Multi-record RRsets and rapid global Anycast propagation. |
Cloudflare DNSGlobal | Verified supported Hands-on test Verified: Sep 28, 2026· Hands-on test: Sep 28, 2026 | Type: TXT | Name: _for-sale | Content: v=FORSALE1;fval=EUR2500 | Superb DoH propagation. Enter content without quotes in the dashboard. TTL Auto or 300s. Native support for leading underscores. |
INWX (InterNetworX)Germany | Verified supported Provider statement Verified: Sep 28, 2026· Hands-on test: Sep 28, 2026 | Name: _for-sale | Typ: TXT | Wert: v=FORSALE1;fval=EUR2500 | Underscore labels are fully supported in the DNS editor. INWX published an official statement confirming RFC 10023 support at the DNS level (independent of automated marketplace integration). |
Netcup CCP / DNS-EditorGermany | Verified supported Hands-on test Verified: Sep 28, 2026· Hands-on test: Sep 28, 2026 | Host: _for-sale | Type: TXT | Destination: v=FORSALE1;fval=EUR2500 | The Netcup Customer Control Panel (CCP) DNS editor accepts underscores for TXT records without restrictions. |
deSEC.ioGermany (Open Source) | Verified supported Hands-on test Verified: Sep 28, 2026· Hands-on test: Sep 28, 2026 | Subname: _for-sale | Type: TXT | Value: "v=FORSALE1;fval=EUR2500" | Free non-profit DNS provider with automatic DNSSEC signing of the RFC 10023 record. Full API and web interface support. |
StratoGermany | DNS syntax supported Official documentation Verified: Sep 28, 2026 · RFC 10023 test: not performed· Native integration: unconfirmed | TXT-Präfix: _for-sale | Official FAQ describes TXT prefixes. Historical reports of rejected underscores in legacy packages are not documented in current help resources. Classified as unclear pending hands-on verification. |
IONOSGermany | DNS syntax supported Official documentation Verified: Sep 28, 2026 · RFC 10023 test: not performed· Native integration: unconfirmed | Hostname: _for-sale | Record: TXT | Official IONOS documentation confirms support for leading underscores in TXT hostnames (e.g. for _dmarc). A dedicated hands-on test for _for-sale and native RFC 10023 marketplace evaluation are currently unconfirmed. |
OVHcloudFrance / Europe | Verified supported Official documentation Verified: Sep 28, 2026 · RFC 10023 test: not performed· Native integration: unconfirmed | Subdomaine: _for-sale | Type: TXT | Valeur: "v=FORSALE1;fval=EUR2500" | OVHcloud Web Cloud DNS zone editor and text mode support TXT records for subdomains without underscore restrictions. |
Hetzner DNS Console
GermanyName: _for-sale | Typ: TXT | Wert: v=FORSALE1;fval=EUR2500Hetzner supports leading underscores (RFC 8552) without warning in both the web console and DNS API. Multi-record RRsets and rapid global Anycast propagation.
Cloudflare DNS
GlobalType: TXT | Name: _for-sale | Content: v=FORSALE1;fval=EUR2500Superb DoH propagation. Enter content without quotes in the dashboard. TTL Auto or 300s. Native support for leading underscores.
INWX (InterNetworX)
GermanyName: _for-sale | Typ: TXT | Wert: v=FORSALE1;fval=EUR2500Underscore labels are fully supported in the DNS editor. INWX published an official statement confirming RFC 10023 support at the DNS level (independent of automated marketplace integration).
Netcup CCP / DNS-Editor
GermanyHost: _for-sale | Type: TXT | Destination: v=FORSALE1;fval=EUR2500The Netcup Customer Control Panel (CCP) DNS editor accepts underscores for TXT records without restrictions.
deSEC.io
Germany (Open Source)Subname: _for-sale | Type: TXT | Value: "v=FORSALE1;fval=EUR2500"Free non-profit DNS provider with automatic DNSSEC signing of the RFC 10023 record. Full API and web interface support.
Strato
GermanyTXT-Präfix: _for-saleOfficial FAQ describes TXT prefixes. Historical reports of rejected underscores in legacy packages are not documented in current help resources. Classified as unclear pending hands-on verification.
IONOS
GermanyHostname: _for-sale | Record: TXTOfficial IONOS documentation confirms support for leading underscores in TXT hostnames (e.g. for _dmarc). A dedicated hands-on test for _for-sale and native RFC 10023 marketplace evaluation are currently unconfirmed.
OVHcloud
France / EuropeSubdomaine: _for-sale | Type: TXT | Valeur: "v=FORSALE1;fval=EUR2500"OVHcloud Web Cloud DNS zone editor and text mode support TXT records for subdomains without underscore restrictions.
Technical Background: Why do some hosters reject underscores?
Historically, the standard for hostnames (RFC 1035 / RFC 1123) only permitted characters [a-z0-9-]. However, the Domain Name System protocol itself allows arbitrary octets under RFC 2181. For service records and global attributes, the IETF formalized underscored leaf nodes in RFC 8552 (such as _dmarc, _domainkey, and now _for-sale). Modern DNS providers support this fully; older control panels still erroneously validate input against strict hostname syntax.
Recommended DNS Providers
For managing portfolios and utilizing RFC 10023 flexibly, choose providers with modern DNS engines: Cloudflare DNS, Hetzner DNS Console, INWX, or deSEC. Records can be created without validation errors and propagate globally within seconds.
Workaround for Restrictive Hosters
If your hoster’s web control panel rejects underscore characters, you can delegate your domain’s authoritative nameservers to Cloudflare or deSEC free of charge. Your domain registration remains unchanged with your existing registrar.