Hi all

I'm trying to create the opentype for Small Caps.
I have two classes, smcp1 and smcp2 which contain the lowercase and small caps.
In the Opentype window I have the feature 'smcp' with


feature smcp {
sub @smcp1 by @smcp2;
} smcp;


When I compile I get the following warning:

Feature block seen before any language system statement. You should place language system statements before any feature definition.

What is a language system statement?

How do I place language system statements before any feature definition.