Great description of the nuance between Systems Hungarian and Apps Hungarian.
One further nuance is that return types of APIs also affect the naming of the APIs in Apps Hungarian. Boolean return values are typically called f for flag. An API that returns a boolean would be called FApiFunction - the capital F (camel case is used) at the beginning of the API name indicates that the API returns a boolean. If you write code that stores the return value in a variable that doesn't begin with an 'f' then any code reader would see the mismatch.
FTA, one problem is that the API returns a ULONG where 0 is failure and non-zero is success.
But the developer thought that the API returned an NTSTATUS error code, where 0 (== STATUS_SUCCESS) is success and non-zero is failure. This is the opposite of the documented return value for the API in question.
In Apps Hungarian, the naming of the API would be obvious that it didn't return an NTSTATUS variable vs a ULONG. Systems Hungarian lost that tidbit somewhere. So developers must be more diligent about knowing the return values of various APIS (but assuming NTSTATUS usually works, expect in this case).
But Apps Hungarian rarely names variables with native type prefixes. Variables are more than just the native underlying type (ULONG, int). Variables have a purpose. The return type of strlen or Win32 equivalent is an int or for more modern-designed APIs, an unsigned int (since string lengths can't be negative). In Systems Hungarian, you'd name the variable ulen. But in Apps Hungarian, strlen returns an int representing the count of characters. Apps Hungarian uses 'ch' for character and 'c' to denote a count. So the variable used to store the return value from strlen would be cch. (And in Apps Hungarian, you'd actually alias strlen to CchStrlen so you'd know just looking at the API that it returns a 'cch', count of characters, and you'd need a CCH type to store the return value).