getConsentData and consentStringVersion about gdpr-transparency-and-consent-framework HOT 1 CLOSED

What does it mean to fetch different versions of the consent string? As far as I can tell, there is one consent string stored at the "euconsent" key on the consensu.org cookie.

Right now there is only one version of the consent string (v 1) I think this was added to the spec to allow for the possibility of more versions, although I agree it's a little unclear as to how it would be possible to store more than one version of the consent string on the consensu.org domain at this time. I think the issue will become a bigger deal when/if we move to a v2 of the consent string. Some CMPs will be writing v2 consent strings and other v1 and some ad tech on the page will need a v1 or a v2 consent string etc.

Does that mean the argument passed to the callback should be null (I guess "returns" means "supplies to the callback" in this context)? Or does it mean just the consentData property of the provided callback should be null?

Look at the documentation a little more closely on how the function works. It follows the format:
__.cmp("METHOD NAME", Arguement, callback(callback parameter) {});

from gdpr-transparency-and-consent-framework.