If we compile our last version of the cabin, we get a room where the glass case and the bench are listed separately from the room description, even though they have already been mentioned once. We can prevent this by making the already-mentioned things scenery:
Generally speaking, it is a good idea to recognize the player's attempts to interact with any objects mentioned in the room description, so we should also provide
Test me with "examine instruments / x windows / x sign / x display / x radios".
The front of the small cabin is entirely occupied with navigational instruments, a radar display, and radios for calling back to shore. Along each side runs a bench with faded blue vinyl cushions, which can be lifted to reveal the storage space underneath. A glass case against the wall contains several fishing rods.
Scratched windows offer a view of the surrounding bay, and there is a door south to the deck. A sign taped to one wall announces the menu of tours offered by the Yakutat Charter Boat Company.
> examine instruments
You see nothing special about the navigational instruments.
> x windows
You see nothing special about the scratched windows.
> x sign
You see nothing special about the sign.
> x display
You see nothing special about the radar display.
> x radios
You see nothing special about the radios.
The door and the view will need to be done as well, but they are special cases which we will get to shortly.
As noted, making something scenery also means that the player will be prevented from picking it up and carrying it away. This is sensible, though: if an object can be removed from the room where it first appears, we should be careful about mentioning it in the main room description; otherwise, it will continue to be described as present even when someone has carried it off.