We're designing short informative messages to be displayed as feedback on a design application. The usage of a particular type of lens is either recommended or recommended against.
The positive message is:
Type-1 lens recommended for this design
For the negative message, we could have:
Type-1 lens not recommended for this design
But I'm not sure this is assertive enough, since we want to actively advise against using it, and this sounds neutral to me (We don't recommend it, but we aren't recommending against it, if you know what I mean). I thought of:
Type-1 lens discouraged for this design
but I'm not sure if it's correct, or if it sounds weird.
It would be easier if we used active sentences ('We recommend' as opposed to 'This is recommended'), but we prefer to keep a passive voice.
Is there a good option?