Campaign finance rules just got a bit stricter in Philly. And they will be enforced.

In 2023, Philadelphians will vote for a new mayor. They will also choose candidates to fill other important city offices. Millions of dollars will be spent by hundreds of political committees to influence who we vote for in each of these races — but the largest amount of money will likely be spent on the mayor’s race.

As the chair and executive director of the Philadelphia Board of Ethics, which enforces campaign finance rules, we want to send a message to all candidates and political committees: We are watching.

The city has contribution limits enforced by the Philadelphia Board of Ethics that are designed to restrain the influence of large donors on city contracts and policies. Specifically, campaigns cannot accept more than $12,600 in contributions from an organization.

However, the U.S. Supreme Court’s decision in Citizens United v. FEC issued in 2010 significantly deregulated money in politics and strengthened the influence of large donors, especially at the federal level.

What did Citizens United mean for Philadelphia? It meant that “independent expenditure committees” — as they are now known under Pennsylvania law — can raise and spend unlimited amounts of money, including money from corporations and unions, but only if they refrain from making direct or indirect contributions to candidates or “coordinating” with candidates. In other words, organizations can throw as much money at the 2023 mayoral candidates as they want, but they have to play by the rules.

This ability to raise unlimited amounts of money is why these independent committees are often called “super PACs.”

In order to ensure super PACs remain truly independent, courts and regulatory agencies like the board enforce rules against “coordination” between candidates and super PACs. Coordination can include activity where a candidate helps a super PAC plan how the PAC spends money, gives the PAC materials to use for “republication” (which could include using campaign materials in political ads by the PAC), or helps the PAC raise money, even up to a year before the election.

When super PACs coordinate with candidates, they are no longer acting “independently” and are breaking the rules. Coordination is a way to circumvent the city’s contribution limits, which is not fair to other candidates who follow these rules.

“[Coordination with super PACs] is not fair to other candidates who follow these rules.”

If a super PAC spends money in coordination with a Philadelphia candidate, that activity is no longer considered an independent expenditure — and if that money exceeds the city’s contribution limit, it would be considered unlawful. For example, if a super PAC works with a candidate on a $500,000 TV ad buy, the board can ask a Philadelphia Court of Common Pleas judge to order the super PAC to stop its advertising plan and levy financial penalties against the super PAC for any related campaign finance violations, because such a coordinated ad buy would be a contribution that exceeds the city’s $12,600 limit.

While there may or may not be violations for the candidate, people running for public office in Philadelphia should think carefully before agreeing to have their campaign financially boosted by such a rule-breaking scheme.

Unlike federal elections, where the rules and enforcement have struggled to keep pace with the emerging ways candidates and super PACs coordinate, Philadelphia has tracked the latest super PAC trends around the country since Citizens United and has amended and refined its campaign finance rules — as recently as this summer.

Our latest update over the summer addresses the newer trend of “redboxing,” where candidates place instructions in red boxes on their campaign websites. Super PACs interpret these instructions as directions on what information the candidates want super PACs to include. The instructions are often thinly veiled – for instance, a campaign may say a message should reach voters “on the go,” which means it should be part of a mobile ad. So make no mistake: Redboxing is a means of circumventing the rules against super PACs directly coordinating with the campaigns they support.

» READ MORE: Philly’s Board of Ethics voted to close a loophole that super PACs use to get instructions from campaigns

In September, Philadelphia became the only jurisdiction in the country that we know of to address redboxing, when the Board of Ethics unanimously voted to regulate the strategy. Redboxing has been used in federal campaigns around the country, but complaints to the Federal Election Commission have mostly gone unheeded.

We hope this sends a message to Philadelphia candidates that running for office in this city is not like running for federal office. That message is: Philadelphia has different rules. And they will be enforced.

Michael H. Reed and J. Shane Creamer Jr. are the chair and executive director, respectively, of the Philadelphia Board of Ethics, a five-member volunteer city agency that is independent of the administration.