As described in the Improving Setting Validation in the Customizer proposal post and detailed in #34893 and #36944, WordPress 4.6 includes new APIs related to validation of Customizer setting values. The Customizer has had sanitization of setting values since it was introduced. Sanitization involves coercing a value into something safe to persist to the database: common examples are converting a value … Continue reading Customizer APIs in 4.6 for Setting Validation and Notifications