Any matching word will be assigned to a default slot name. If you are writing a grammar for a mixed-initiative form, you may use multiple slot names, each identifying a field item variable to be filled. In this case you can name each field according to the corresponding slot name in the grammar. Suppose the following rule is defined as the grammar for a mixed-initiative form. A grammar is ambiguous if more than one rule that can match a given user utterance.
Ambiguous grammars can be a problem if the different rules make different slot assignments.
In general, you should avoid using ambiguous grammars. If you choose to use them, you need to enable recognition of multiple interpretations of the user's speech and implement a mechanism to get user clarification for ambiguous utterances. An external grammar described in a separate file. A rule set containing a number of named rules that can be used as subgrammars by other grammar rules. Using an Inline Grammar To include a grammar description directly in your VoiceXML code, embed it inside the grammar tag.