# CII-SR-090

Source: https://xmlvalid.com/rules/CII-SR-090

> ID should exist maximum once.

- Level: error
- Rule sets: EN 16931 rules (CII) 1.3.17, EN 16931 rules 1.3.16 (CII), EXTENDED-CTC-FR rules (CII) 1.4.0.04
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedTradeProduct`
- Test: `not (ram:OriginTradeCountry) or (count(ram:OriginTradeCountry/ram:ID) =1)`

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