Each feature is represented as a three letter abbreviation taken from a standardized set. A first cut at the feature set appears in appendix A below. This works, but it's a bit of a pain. The segment symbols are given in appendix B below. The features which the diacritics map to override those of the segment.
Some diacritic symbols encode more than one feature set.
Which one is meant should be apparent from context. The complete set of diacritic symbols appears in appendix C below. Such an alteration should be made explicitly to avoid confusion. Such symbols can be assigned either by convention for a specific language or in an ad-hoc manner by an individual author. Stress marks are prepended to the syllable they attach to.