I was writting when rejetto post before me....
The utility of such an action is to prevent the recursive questions on the use of new macros, which would provoke inevitably some bugs on new template with old version of HFS
Of more the solution of rejetto imply a message on the utilisteur, while I propose an alert at the level of hfs, what adorned me more logical, instead of testing templates from every angle and allowing to pass an error
I have already tested the solution of rejetto but it did not seem to me sufficient(self-important), where from my proposition of macro with a message of alert at the level of the server