When an availability block is created in Mews, a new rate is created, dedicated to this block. The new rate is based on an original rate, taken from the list of rates already existing in Mews. Let's say a hotel has a company profile "Company X" which books a conference. The user selects rate = "Company X corporate rate" and Mews creates a copy of this rate and attaches it to the block. When fetching the block via the API, the block references this copy as its rate ID.

We want to know what the original/underlying rate is for such block rates. Our motivation is the following: When showing statistics for rate codes, we want to aggregate figures by the original rate instead of showing separate figures for each availability block rate code. In the user's mind, only one "Company X corporate rate" object exists in the system, and showing separate statistics for tens or hundreds of different availability block rates derived from the corporate rate, all named similarly, will be confusing and provide little value to the user.

To achieve this we need a way to trace availability block rate objects back to their original rate. However, the API doesn't contain any field that specifies this. We would like to be able to trace the path from an availability block rate back to the original underlying rate via a dedicated field that references the original rate's ID.