The meta-data are some sorts of answers that you attribute to the respondents before they have even started answering the questionnaire. This can be information that you already know (already have in your database) and you do not need to ask again: phone number, zip code...etc). This can also be data that you want to use during the mail merge (to customize the emails...that is why you add the meta-data at this step). You will be able to use the meta-data as standard answers and do the same analyses as the Single choice questions.