Mentioning Undescribed Objects in Non-Starting Rooms

So I’m a very new (one week) to Inform 7, and am still working on just a basic program and using google to teach myself. But now I’m trying to clean it up a bit and get rid of the pesky double mentioning of items in rooms where you write about them in the description.

For the time being I’ve been using “[Noun] is undescribed.” Like this:

On the counter is a knife. The knife is undescribed. The knife is portable. The description of Knife is "It hurts just to look at."

But then if the player carries it to a room where it doesn’t show up in the room description and drops it, it won’t be listed there either, which is a problem.

By reading other threads I came up with a solution of using the Mentioned in Room Description extension by Ron Newcomb, but when I download it, Install it, and try to include it, it comes up with an error. So is there any other way of not listing an object in the room it starts in where I talk about it in the description, but listing it everywhere else?

Thanks.

It looks to me as though the functionality of the Mentioned in Room Description extension may now be automatically included in version 6L02 of Inform. So trying this code:

[code]Kitchen is a room… “A kitchen with [a counter][if the knife is on the counter], on which is [a knife][end if].” The counter is a scenery supporter in the Kitchen.
On the counter is a knife.
The description of Knife is “It hurts just to look at.”

The Living Room is south of the Kitchen.[/code]

the counter and knife don’t show up in “You can see…” paragraphs if they’re, well, mentioned in the room description. But if you pick the knife up and drop it on the floor, it will get a “You can see…” paragraph because it’s not mentioned in the room description anymore. So:

ETA: Yep, from the 6L02 changelog:

That works perfectly, thanks. I’m pretty sure I tried to do that once myself but messed it up and assumed it didn’t work, but I’ve got it working now.