Perfect Dark/Unused Content By Level/Carrington Institute

Front Doors
The slanted portion of the CI's front door model actually rotates upright as it opens. This is never seen because the doors are always locked during training, and knocked out of their frame in the Defense mission.

CI Door 1
A bluish metal door with a concave diamond shape where the knob would be.

Furniture
There are seven furniture models intended for the Institute that aren't utilized. This furniture has a completely different aesthetic than what ended up being used. All of it also lacks the reflection model that the blue sofa actually used in the Institute has.

Carrington's Office
There is a square made up of 20 pads bordering the door of Carrington's safe. This is reminiscent of the floor hatch in GoldenEye's Train mission, where the plates bolting the hatch in place had to be destroyed in order to release the hatch. In Defense, however, Joanna simply has to destroy the safe's door. The screenshot here is using crate objects on the pads since it is unknown what, if anything, was placed on them.

There is also a pad for another safe door. Unlike the safe door that is used, which is just a standard object, this one is set up to use an actual door object, and as such can be opened rather than just destroyed. The pad is rotated so that a normal horizontal opening door will open vertically. It's also slightly smaller than the final safe door and is quite a ways out from the wall, implying a different layout for Carrington's office.

Hangar Area
There is a pad for a door in this frame, which is in the hall that leads to the helipads.

There are three pads which would have let the glass guardrails bordering the catwalks in the hangar to continue on the ramps. Placing the diagonal glass object on these pads reveals that two aren't rotated correctly, and that the third does not align with the guardrail perfectly.

Other
There are ten pads floating in the void beyond the second set of entrance doors. The five large flat pads were intended for window panes, while the four stacked pads were likely a laser grid. The smaller flat pad may have been for a switch. It's unknown if these are remnants of a lost section of the Institute or pads which were misplaced, intended for other rooms. The laser grid, in particular, is perfectly aligned with the safe in Carrington's office.

Unused Textures
This black and white portrait of Daniel Carrington is found amongst other textures used in the Institute.

Organization Bios
The dataDyne Corporation and Carrington Institute both have bios. These are found after the character bios, story, and background entries used in the information room PC. While the Institute does have an entry on the PC in the hangar, it is referring to the building itself, not the organization.

N-Bomb Description
This Maian grenade plays havoc with the neurons in sentient creatures. If you wander into the blast radius, your vision will blur and you will lose your grip on whatever you're holding. The grenade can be set to go off on impact or by proximity trigger. Make sure you throw it far enough away. The N-Bomb has a description for use in the firing range's menu. It reveals the grenade to be of Maian origin, something not mentioned anywhere else in the game and inconsistent with the N-Bomb's appearance. If the N-Bomb is hacked into the list of weapons available in the firing range, this description will be shown when starting a course with it, but it is not possible to pass since the N-Bomb cannot destroy targets.

Golden Guns
The weapons from GoldenEye in the display cases outside of the Carrington Institute's firing range were intended to display their names when interacted with. Unfortunately, while the action block controlling this display is set up properly, the developers forgot to set the bitflag that allows interaction on the weapons, so it can never execute.

Bizarrely, with the exception of the PP7, the weapons are using their real names and not the fictional ones used in GoldenEye or Perfect Dark.

Unused Dialogue
Well, at least I won't know if I'm doing anything wrong. Like much of the unheard dialogue, this is technically used in an action block, but it can never trigger. It was likely recorded for the disarm bomb objective. The briefing for the 4.4 beta makes it sound as if Joanna actually had to disarm the bomb herself, rather than reprogramming the Skedar shuttle on the helipad.

Unused Text
Obtain sensitive info. Sensitive info Picked up sensitive info. These are assigned to the "sensitive information" inside Carrington's safe, which is intended to display as a briefcase in the inventory. The sensitive info cannot be collected, however, so the strings can never be seen. Additionally, despite the suitcase in Air Base sharing its prop model, the briefcase does not have a model in the inventory.

You have been given a Devastator. This was probably intended to be displayed after rescuing Grimshaw or when picking up the Devastator he drops.