Email template

Is it possible to override email notification template to hide some fields , without loosing changes on next upgrade ?

ex:
Content title:{hide} project title

Content State: Published {hide}


Category assignments : {hide}
1. PARTNER SEARCH listing


***************************************************************
Introductory text (for category view) {hide}
***************************************************************
full text goes here...

The email notifications work, features exceed our initial plans by far,
but templating was not added (instead we have many customization parameters per Content Type)
possible some sort of templating can be done in future,

-- But for hiding email data you can do it per Content Type via parameters !!

-- Avoiding hacking CORE files doing this unless very necessary