ACBS offers many types of Continuing Education credits at our training events.
Most of those CE programs require that we have a CVs/resume/bio on hand for each "presenter". (If someone is a co-author, but not going to be delivering the presentation on site, we don't need her/his CV.)
The APA for example explains it this way:
Although it is not required that instructors be psychologists, they must have expertise and be competent in the areas in which they teach. Expertise might be demonstrated by some combination of the following: relevant educational experience such as holding a doctoral degree in psychology, review of records of previous teaching experiences, years of clinical experience, publications in areas relevant to the content being taught, evaluation forms from previously offered programs, personal knowledge of the instructor’s teaching ability, and references.
Collecting CVs is our way of retaining "proof" of your knowledge/competency.
The NASW, for example, requires all CVs to be sent to them prior to CE approval.
If you do not have a CV, or do not have one in English, you may substitute a narrative paragraph, with your name, email address, brief educational background (degrees and training), brief work history (jobs held), and any extra information to support your suitability to train.
Why haven't I been asked for a CV for other conferences?
Usually CEs are only offered for workshops, due to expense and effort, so if you weren't delivering a workshop at another group's conference they likely weren't offering CEs for your presentation, and didn't need your CV.