[AlphaCommerceHub] Why does the documentation say that the `RefundReason` request parameter's type is «Alpha» (not «Numeric») if only the 1..5 digital values are allowed?

The RefundReason request parameter is specified in the «API Integration Guide(Nov 2017)» → «API Reference» → «Request Message» documentation section:

Parameter Name Type Mandatory Description
RefundReason Alpha O The reason for the refund
1 – Product damaged
2 – Customer cancelled
3 – Customer returned
4 – Customer dissatisfied with product
5 – Customer dissatisfied with service

I have got a response from AlphaCommerceHub:

RG: The numeric values are what are supported today but we may accepted other values in the futuer. Field type will be changed in documentation to AN