Identifies a resource or function in a module.
This can be a WORD-sized integer value (0-65536), or string/unicode
depending on whether the *A or *W API function is to be called.
Class atoms as used with win32gui::CreateWindow are also treated
as resource ids since they can also be represented by a name or WORD id.
When passing resource names and types as strings, they are usually formatted
as a pound sign followed by decimal form of the id. ('#42' for example)