Here in the UK almost all "Chili Powder" sold is a cocktail of spices (mainly cumin, paprika and cayenne) and flavourings which does a passable job in producing an ordinary chili con carne. It often comes in mild or hot versions, and I'm happy to use the mild sort, usually with sliced fresh chilis to give some heat.
In the US, however, it seems that chili powder is a pure hot powder, which, when I've found it in the UK (Rajah brand), appears to be identical to cayenne.
Are they one and the same please? Do some recipes call for both chili powder and cayenne?