The US Securities and Exchange Commission (SEC) recently published a request for information and comment on how broker-dealers and investment advisers use digital engagement practices (DEPs) — behavioral prompts, differential marketing, "gamification," and other design elements and features that firms use to engage with retail investors through digital platforms and mobile applications.  The SEC request is long and detailed — more than 70 pages — comprising reminders of existing legal and regulatory standards, descriptions of the SEC’s take on current practices, and many specific questions of interest for comment, along with a general request for comment to cover the possibility that even with all of that detail, something may have been missed. Comments are due 30 days after publication in the Federal Register.