I want to know the answer to the following question:
What encoding does Charis SIL use?
All the background I'm provided with is that "Unicode characters that map to precomposed glyphs can be used in many cases, thus avoiding the problem, but where no precomposed character has been encoded the problem can often be solved by using a specialist Unicode font such as Charis SIL that uses Graphite, OpenType, or AAT technologies for advanced rendering features.". Is that enough to answer the question?
Answer: yes