Upvoted. In the meantime any time I've had to do this in a skill, I've used a custom slot type "alpha_char" which expects [0-9][A-Z]. For the [A-Z] each letter has its phonetic alphabet equivalent as a synonym (alpha, bravo, charlie, etc). This works well except for a single case of intent confirmaiton: if the input slot sequence has a digit adjacent to an 'N' and the customer says 'November' (the phonetic for N), intent confirmation doesn't work well. It interprets "3 November" or "November 3" as a date. There's no way for the skill to override this as the confirmation is upstream of the request being delivered. So only recourse is to disable confirmation and do that in the skill itself, which is messy. Something to keep in mind if this makes it to implementation.
Upvoted. In the meantime any time I've had to do this in a skill, I've used a custom slot type "alpha_char" which expects [0-9][A-Z]. For the [A-Z] each letter has its phonetic alphabet equivalent as a synonym (alpha, bravo, charlie, etc). This works well except for a single case of intent confirmaiton: if the input slot sequence has a digit adjacent to an 'N' and the customer says 'November' (the phonetic for N), intent confirmation doesn't work well. It interprets "3 November" or "November 3" as a date. There's no way for the skill to override this as the confirmation is upstream of the request being delivered. So only recourse is to disable confirmation and do that in the skill itself, which is messy. Something to keep in mind if this makes it to implementation.