Clearly Siri has a broad knowledge of vocabulary in a wide range of languages. It is quite possible, however, that your app or app users might use certain words or terms which have no meaning or context for Siri. These terms can be added to your app so that they are recognized by Siri. These custom vocabulary terms are categorized as either user-specific or global.
User specific terms are terms that only apply to an individual user. This might be a photo album with an unusual name or the nicknames the user has entered for contacts in a messaging app. User specific terms are registered with Siri from within the main iOS app (not the extension) at application runtime using the setVocabularyStrings(oftype:) method of the NSVocabulary class and must be provided in the form of an ordered list with the most commonly used terms listed first. User-specific custom vocabulary terms may only be specified for contact and contact group names, photo tag and album names...
