The abilITy to accept input from later versions of ITself. Forward compatibilITy is harder to achieve than {backward compatibilITy}, since, in the backward case, the input format is know whereas a forward compatible system needs to cope gracefully wITh unknown future features. An example of future compatibilITy is the stipulation that a web browser should ignore HTML tagsIT does not recognise. See also extensible. (2003-06-23)