The Lobbying Act identifies two groups of people, public office holders and then designated public office holders. Public office holders are practically all public servants, members of Parliament, senators and their respective staff, and GIC appointments. If somebody communicates with any of them, they must register as a lobbyist.
Designated public office holders are ministers and their staff, senators, members of Parliament. When the lobbyist communicates with them, they have an additional burden to do a monthly communication report. They actually have to go in the system to add that they've had a discussion with these people, but these designated public office holders are also individuals who are prohibited from lobbying when they leave office.