The arguments to a template do not necessarily have to be defined to be used. The use of "class roman" actually declares the class roman.

Here is some example code:

#include <iostream> template <class T> void foo(); template<> void foo<class roman>() { // allowed because roman is declared roman* pointer1; // not allowed because romania is not declared // romania* pointer2; std::cout << "Hello world!" << std::endl; return; } int main(int argc, char** argv) { return 0; }

As people have pointed out in the comments above, this distinguishes this instantiation of the template. And to directly answer the question you had, specifying the nature of the template argument in a template instantiation is called an 'elaborated type specifier'.