Hungarian notation is the system used by most C and C++ developers (including those at Microsoft). It's a complete naming system created by Microsoft Distinguished Engineer Charles Simonyi. Back in the early 1980s, Microsoft adopted this famous-or infamous, depending on your point of view-naming system based on ideas from Simonyi's doctoral thesis, "Meta-Programming: A Software Production Method." -
Hungarian notation specifies that a prefix be added to each variable to indicate its type. However, not every type was given a standard prefix. In addition, as other languages were introduced and new types created, new prefixes had to be created. This is why even if you go into a shop that employs Hungarian notation, you might see some prefixes you're not accustomed to seeing. (By the way, the term "Hungarian notation" comes from the fact that the prefixes make the variables look as if they are written in a language other than English; plus, Mr. Simonyi is from Hungary.) -
Perhaps the most important publication that encouraged the use of Hungarian notation was the first book read by almost every Windows and OS/2 developer: Charles Petzold's Programming Windows (Microsoft Press), which used a dialect of Hungarian notation throughout its demo applications. In addition, Microsoft employed the notation in its own development. When MFC was released, a bunch of new prefixes specific to C++ development were released with its source code, thereby guaranteeing the continued use of Hungarian notation.
So why not simply continue using Hungarian notation? Because Hungarian notation is useful in situations where it's beneficial to know the type, or scope, of a variable being used. However, as you'll see in more detail in the next chapter, all types in C# are objects and based on the .NET System.Object class. Therefore, all variables have a basic set of functionality and behavioral characteristics. For this reason, the need for Hungarian notation is lessened in the .NET environment.
For the curious, or for those suffering from insomnia, the original paper that presented Hungarian notation can be found at http://msdn.microsoft.com/library/techart/hunganotat.htm.