The Collator object supports different levels of decomposition and strength. How do I choose the right decomposition and strength in a locale?
Since decomposing takes time, turning decomposition off makes comparisons go faster. However, for Latin languages the NO_DECOMPOSITION mode is not useful if the text contains accents. You should use the default decomposition unless you really know what you’re doing. The strength property you choose depends on what your application is trying to accomplish. For example, when performing a text search you may allow a “weak” match, in which accents and differences in case (upper vs. lower) are ignored. This type of search employs the PRIMARY strength. If you are sorting a list of words, you might want to use the TERTIARY strength. In this mode the properties that must match are the base character, accent, and case.
