# Data Attributes Taking the common baseline set of requirements, we were able to drill down into the three main components further to reflect what we considered the key attributes of retail mortgages that were relevant for this POC. ![Retail Mortgages Main Components](https://firebasestorage.googleapis.com/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mi5wPkxf94vt5dSbr_p%2Fuploads%2FtHgzJg2a3XTd8sKzk7AS%2Ffile.png?alt=media) These data attributes were also intended to be used to calculate or aggregate supervisory metrics. For example, "loan size" and "value of property" would be the key inputs to derive the loan-to-value measure. Other types of aggregation would also be enabled, such as loan-to-income, total loans issued by postcode or total loans issued by purpose (eg owner-occupied or buy-to-let investment). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.bis.org/ellipse/proof-of-concept/data-attributes-and-definitions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.