The Unreal Engine has some rather nifty functionality for dealing with localization. We have also made numerous modifications to facilitate our workflow, but I’ll stick to what is in vanilla Unreal (this is based on 4.25).

There are three different string types to use within Unreal:

• FString: These are traditional strings most people are used to. When creating a new string it will allocate memory to store the data. Equality comparisons need to check the actual string data.
• FName: When you create a name, it is stored in a table in memory permanently (there is no clean up of unused names). Two FNames with the same value point to the same index, which makes equality comparisons very fast: they just compare indices. But the memory usage can grow without bound.
• FText: These are localized strings that go through a process of being gathered, translated, and having their values stored in a separate file called a locres file. When evaluating an FText, there is a lookup for the actual value to use.

Epic provides a tokenization system using curly braces, { and }, where you can provide parameters (either positional or named) for an FText format string.

However, we added another one using square brackets, [ & ], where we would take the token within and look up the value as an FName in various tables that were provided to look up information.