# CF406

Source: https://xmlvalid.com/rules/CF406

> Enter valid SST registration number - …: letters, digits and dashes, at most two numbers separated by a semicolon, up to 35 characters, or NA.

- Level: error
- Rule sets: MyInvois validations of LHDN (Malaysia) MyInvois SDK of 25 September 2026
- Context: `/*/cac:AccountingSupplierParty/cac:Party | /*/cac:AccountingCustomerParty/cac:Party`
- Test: `every $s in $sst satisfies (string-length(normalize-space($s)) le 35 and matches(normalize-space($s), '^(NA|[A-Za-z0-9-]+(;[A-Za-z0-9-]+)?)$'))`

Validate a document against these rules: https://xmlvalid.com/validate