When working with a Communication Preferences form in BBIS, one may notice it appears the form requires users to be registered with the Community before they can opt-out of emails despite users not being required to be registered users when opting-in. The BBIS Forms Guide also seems to support this (https://www.blackbaud.com/files/support/guides/enterprise/400/formsec.pdf, p. 17):
Note: Use the Communications Preferences form so registered website users can select the types of mail and email communications they want to receive. You also use this form to provide a way for these users to opt out of communication from your organization.
The User Email Preferences Form appears when users access it from links in email, regardless of whether they are logged in. However, if users access the form through the website, it only appears when they are logged in.
This KB serves to bridge this gap in information between the two guides.