This summary is not the rule. The rule text controls.
When a lawyer speaks to a lawmaking group or government agency on behalf of a client, and the matter isn't a formal hearing or trial, the lawyer has to make it clear they are there representing someone else. They can't pretend to be speaking as a private citizen or a neutral party.
The lawyer also has to follow the same honesty and fairness rules that apply in courtrooms. This means they can't lie to the legislative body or agency, can't hide important facts they're required to share, and can't try to destroy evidence or push witnesses to avoid testifying or to change their testimony. They also can't try to improperly influence the officials involved, such as through bribery or backdoor pressure.
Basically, this rule makes sure that even outside of court, when lawyers are dealing with government bodies making decisions or rules, they still act honestly and openly about who they represent. It stops lawyers from using shady tactics just because they're not in a courtroom setting.