CF-remove-field-from-entry.php

<?php
/**
 * Delete one field's value after Caldera Forms sends main mailer
 */
add_action( 'caldera_forms_submit_complete',
    function( $form, $referrer, $process_id, $entry_id ){
        //IMPORTANT: Change form ID here
        $form_id = 'CF123456';

        //IMPORTANT: Change field ID here
        $field_id = 'fld_8768091';

        //Only run on this form
        if( $form[ 'ID' ] == $form_id ){
            //check if field is present in form
            if( is_array( Caldera_Forms_Field_Util::get_field( $field_id, $form ) ) ){
                //Delete just this one field's value
                global $wpdb;
                $wpdb->delete( $wpdb->prefix . 'cf_form_entry_values', array(
                    'entry_id' => $entry_id,
                    'field_id' => $field_id
                ) );
            }


        }


    },
    //Priority 26 is one higher than priority used to send main mailer
    //If priority was 24, field would not be included in email
    26,
    //4 args needed so we can get entry ID
    4
);