THE .SI FIELD GUIDE
.si internationalized domain names
Supported .si international characters, Punycode and length rules.
.si supports internationalized domain names from a published Latin character table. A readable IDN must contain at least two characters and its ACE encoding must fit within 63.
Use the allowed character table
The registry’s table includes Slovenian letters č, š and ž, plus specified Latin supplements and extensions. Support for IDNs does not mean every script or emoji can be registered. Our checker validates against the published table before making a lookup.
Readable name versus ACE
A Unicode name is encoded into an ASCII-compatible label beginning xn-- for technical use. The minimum length is checked on the readable name, so one international character is still too short even if its encoded form is longer.
Make the name usable
Check how the domain looks in your intended browsers, email clients and advertising tools. Test spelling with your audience and watch for visually similar characters. Verify that your chosen registrar supports registering and managing the specific IDN.
Can I register č.si?
No. A single visible character does not satisfy the registry’s minimum of two characters in the textual and binary representations. The character č is among the allowed IDN characters, but that does not override the length rule. A two-character supported Unicode label still needs normalization, an ACE/Punycode length check and an individual lookup. Verify the exact name with the registrar before purchase.
.si domain checker
Primary sources
Registry rules come from Register.si. Delegation comes from IANA. Provider details come from the provider. Availability is checked separately and can change at any time.
How we verify