In Fallout: New Vegas, codes for items from DLCs are represented as xx in item codes, and they start with a unique identifier known as a DLC code.
A DLC code is a two-digit number that indicates to the game which DLC an item originates from.
This code varies for each player because it's determined by both the number and type of DLCs they have installed.
Item codes that begin with
xx pertain to items from DLCs. The
xx acts as a placeholder for the DLC code, which is unique for each player.
This uniqueness arises from the load order of the DLCs, which affects these numbers. The only 'fixed' IDs are those from the 'base' Fallout: New Vegas game, which always start with
00 because it is always the first to load.
In the game, Fallout: New Vegas, you can open the console and click on an object native to the world. The first two numbers of that item's code will represent the DLC code.
If the above method proves ineffective, consider inputting the following numbers in place of the
09... and so on.
One of these numbers should be the correct DLC code.