A valid domain name is subject to the following limits:
- Domain names are case-insensitive and do not distinguish between simplified and traditional Chinese characters.
- A valid domain name must contain 1–63 characters (excluding the suffix).
- A valid English domain name consists of lowercase letters (a–z), numbers (0–9), and hyphens (-). But a hyphen is not allowed in the string head, tail, and the third and fourth character positions.
- A valid Chinese domain name must contain at least one Chinese character (simplified or traditional) in addition to the valid English characters. The length of a Chinese domain name is measured in punycode after conversion.
- Request parameters starting with “xn—“ (punycode) are not supported. You must use a Chinese domain name as the request parameter.