Battlefield 2

Straight Outta Karkand.

M82A1
The M82A1 .50 caliber anti-materiel rifle was originally planned to be included in Battlefield 2 -- however, it was cut pretty early on as its only remnant is its icon and model. When one attempts to manually add the rifle to the sniper loadout, it is instead replaced by the L96A1. The M82A1 was later included in Battlefield 3 as a weapon in the single player mission "Kaffarov", and appears as an obtainable weapon in Battlefield 4.

LP7
The LP7 laser designator was a gadget that was, originally, to be issued to the Spec Ops proven by the code string "rem ObjectTemplate.addTemplate SIMRAD". It is entirely finished, and even has its own icons, sounds, and tutorial pop-up, but was ultimately dummied out. If it had been included, it would have been used to designate targets for jets.

Hingan Hills
A map with the title 'Hingan Hills' can be found in the localization files along with the description: "Military planners for both the US and the People’s Republic of China quickly realized that this sector contains key strategic bridges that provide easy armored access to the Manchurian heartland and deployed accordingly. To secure possession of these vital lines of advance elements of both nations are racing to meet head-on amidst the scattered farms, villages and industrial areas of this ancient, remote landscape." , though it can be found nowhere else in the game files. A similar situation exists with a map known as Divided City, although it seems that one was worked into Mashtuur City.

Unfinished Easter Egg
Each of the voice sets used in the base game has unused voice commands for shouting "Enemy Wheelbarrow Spotted!", usually followed by a laugh or yell. This was apparently planned for an easter egg that DICE didn't have time to add to the game, where a random Wheelbarrow on a map would be usable as a somewhat ineffective vehicle - one player would push it while another would sit in it, gun ready.

VB1
The VB1 was completely deleted from the game, but referenced in the localization files and has a HUD icon. The code strings "KILLMESSAGE_VEHICLE_vb1 DELETED". While a VB1 in real life is a brand of motorcycle, the HUD icon shows an APC type vehicle. The VB1 dirt bike later appeared in Battlefield 3's Endgame DLC.

Euro Force

 * Harrier: A fighter plane. A HUD icon remains along with a mention in the localization files, "KILLMESSAGE_VEHICLE_harrier DELETED".
 * Lynx: A helicopter intended to be the European Union. Again only HUD icon remains and a mention in the localization files, "KILLMESSAGE_VEHICLE_Lynx Lynx AH-7".