# OpenType Feature File specification, section 5.f.ii, example 1
# "Specifying exceptions to the Chain Sub rule"
# http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html

feature test {
    ignore substitute f [a e] d';
    ignore substitute a d' d;
    substitute [a e n] d' by d.alt;
} test;