Unicode supports several phonetic scripts and notations through the existing writing systems and the addition of extra blocks with phonetic characters. These phonetic extras are derived from an existing script, usually Latin, Greek or Cyrillic. Apart from International Phonetic Alphabet (IPA), extensions to the IPA and obsolete and nonstandard IPA symbols, these blocks also contain characters from the Uralic Phonetic Alphabet and the Americanist Phonetic Alphabet.