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The label you choose becomes the left-most part of your subdomain — for example, the label myproject produces myproject.nxtdev.xyz. Labels are validated against a strict set of rules before a subdomain is created. This page documents every rule extracted directly from the platform’s validator.

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Length constraints

ConstraintValue
Minimum length4 characters
Maximum length32 characters
Labels shorter than 4 characters are rejected for regular accounts. Labels longer than 32 characters are rejected unconditionally. The admin team may reserve labels shorter than 4 characters for special purposes.

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Allowed characters

Labels may only contain the following characters:
  • Lowercase letters: a through z
  • Digits: 0 through 9
  • Hyphens: -
No spaces, dots, underscores, or special characters are permitted. Uppercase letters are accepted in the input field but are automatically converted to lowercase before validation and storage.
Lowercasing is applied automatically. Submitting MyProject is identical to submitting myproject. The resulting subdomain is always fully lowercase.

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Forbidden patterns

Even if a label uses only allowed characters, the following patterns cause it to be rejected:
PatternRule
Starts with a hyphenNot allowed — e.g. -myapp is invalid
Ends with a hyphenNot allowed — e.g. myapp- is invalid
Contains consecutive hyphensNot allowed — e.g. my--app is invalid
These restrictions are consistent with standard DNS label rules and the IDNA specification.

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Examples

# Valid labels
alice
my-project
dev42
api-v2
hello-world-2025

# Invalid labels — too short
ab
xyz

# Invalid labels — forbidden characters
my_project       (underscore not allowed)
my.project       (dot not allowed)
my project       (space not allowed)

# Invalid labels — forbidden patterns
-myapp           (starts with hyphen)
myapp-           (ends with hyphen)
my--app          (consecutive hyphens)

# Invalid labels — too long (over 32 characters)
this-label-is-way-too-long-to-be-valid

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Reserved labels

Some labels are reserved by the nxtdev.xyz admin team and cannot be claimed through the normal flow. Reserved labels may be shorter than 4 characters or may correspond to names the platform uses internally.
If the availability checker returns "Reserved - contact Administrator to claim this domain", the label exists in the reserved list. You cannot claim it unless an admin explicitly assigns it to your account.
Reserved labels still follow all character and pattern rules — they are simply blocked from public registration regardless of whether they look syntactically valid.

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Safety system: phishing and impersonation blocks

After structural validation, every label is checked against the platform’s safety system for phishing keywords and impersonation patterns. This check runs even on labels that would otherwise be valid.
Labels that match known phishing patterns or impersonate services (for example, patterns associated with credential harvesting pages) are blocked automatically. The availability checker returns "reason": "Blocked by safety policy". This block cannot be bypassed.
Legitimate project names are never blocked. If you believe your label was incorrectly flagged, contact abuse@nxtdev.xyz to appeal.