The problem is that when I replace lower case with small caps the brackets also reduce in size (shown in pink). There is a similar problem when replacing caps with small caps. As you can see with the illustration the feature code is pretty simple - just replacing one class with another. Could this be something that needs specifying as an exception to the context rule? The FontLab manual has no illustrations which demonstrate the meaning of the text, so consequently means nothing to me. That’s the trouble with the manual; sometimes it has illustrations for obvious things, but none for not-so obvious things.

Any ideas? Thanks.