MaskInputRule SAP SE The <code>sap.m.MaskInputRule</code> control holds the mapping of a single <code>maskFormatSymbol</code> to the regular expression <code>regex</code> that defines the allowed characters for the rule. 1.34.0 sap.ui.core/Element Defines the symbol used in the mask format which will accept a certain range of characters. Defines the allowed characters as a regular expression.