In addition to the marketMedianOracle, the cpiMedianOracle plays a role in understanding the market value of Digg. This oracle is used in the Ampleforth system to track the consumer price index in order to understand the relative purchasing power of a USD over time. In Digg, as BTC is the peg rather than a 2019 USD, the CPI Oracle is effectively unused. Rather than modify the audited Ampleforth code, it was considered perferable to 'disable' this functionality by having the CPI oracle always return "1".