Identifier expected
You did not supply an identifier. An identifier is the name of a class, struct, namespace, method, variable and so on that you provide.
The following example declares a simple class but does not give the class a name:
//XS1001.prg
Parameter names are required even if the compiler doesn't use them, for example, in an interface definition. These parameters are required so that programmers who are consuming the interface know something about the what the parameters mean.
// XS1001-2.prg
// compile with: /target:library