Changes that the American Bar Association adopted earlier this week to its model rules regarding attorney advertising and business solicitation mark a significant step toward clarifying what has been a confusing area of legal ethics, said several lawyers who focus on professional liability issues.

But the new rules also stop short of addressing murky questions about attorney referrals that have arisen in the age of social media platforms, such as LinkedIn, and lawyer review websites, such as Avvo Inc., those lawyers added. And the practical impact of the updates will likely depend on whether and how quickly state bar associations follow the ABA’s guidance.