Abstract system and method for enabling data modification, classification and enforcement of IRM capabilities in standard isolated software applications is disclosed, according to which an add-on code is installed on the terminal device of user that runs the standard application. The add-on code is adapted to interact with the virtual keyboard used by the standard application, to form a custom virtual keyboard to which the features of classifying data items(s) and/or of modifying the content of the data item are added, without changing the natural environment, the user is normally used to. Then a custom virtual keyboard that includes a designed UP interfacing objects is created, for adding inputs that are associated with classification and modification in the data item in the form of a hidden tag tot the content of the data item.