The core CPI index is a price-level index that excludes goods with high price volatility, such as food and energy. This measure of core inflation systematically excludes food and energy prices because, historically, they have been highly volatile.
Matt Yglesias, the blogger and journalist who currently writes at Slow Boring, predicted on December 28th that annualised core US CPI growth will not exceed 2% in any month of 2021 (70% confident), and that it won’t exceed 3% in any month (90% confident).