# CII-FREXT-SR-072

Source: https://xmlvalid.com/rules/CII-FREXT-SR-072

> Value should exist maximum once.

- Level: error
- Rule sets: EXTENDED-CTC-FR rules (CII) 1.4.0.04
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedTradeProduct/ram:ApplicableProductCharacteristic`
- Test: `(count(ram:Value) <= 1)`

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