Occurrences of int, unsigned, and unsigned int indicate potential portability problems because size and range are not constant. Data that would not exceed its range in Win32 could exceed range in Windows 3.x. Sign extension also works differently, so exercise caution in performing bitwise manipulation of this data.
Source code that relies on wrapping often presents portability problems and should be avoided. For example, a loop should not rely on an unsigned variable wrapping at 65535 (the maximum value in Windows 3.x) back down to 0.