Naming Include Guards

Question

How are C++ include guards typically named? I tend to see this a lot:

#ifndef FOO_H
#define FOO_H

// ...

#endif

However, I don\'t think

Answer 1

I normally use something like FOO_H_INCLUDED_. A few (Microsoft) headers have what looks a lot like a string representation of a GUID, but I've never needed anything quite that elaborate.