- * @param {number} step Normal step
- * @param {number|null} pageStep Page step. If null, 10 * step will be used.
+ * @param {number} [buttonStep=step||1] Delta when using the buttons or up/down arrow keys.
+ * Defaults to `step` if specified, otherwise `1`.
+ * @param {number} [pageStep=10*buttonStep] Delta when using the page-up/page-down keys.
+ * Defaults to 10 times `buttonStep`.
+ * @param {number|null} [step] If specified, the field only accepts values that are multiples of this.