Republican Donald Trump delivers remarks at the Shale Insight energy conference in Pittsburgh on Sept. 22, 2016. (Jonathan Ernst/Reuters)

With questions swirling around potential conflicts of interest for lobbyists and family members on Donald Trump’s transition team, ethics experts say it’s crucial that the team building the new administration have a formal code of principles.

But here’s a little-understood fact about presidential transitions: They don’t have to follow a code of ethics unless they want to, and even if they do, they come up with the terms themselves. When Trump communications director Jason Miller was asked whether one existed  Monday, he said he was not sure about the existence of an ethics code, but said he would get back to us.

On Wednesday, Trump’s campaign released to The Post the new ethics rules it is implementing under the direction of Vice President-elect Mike Pence. Pence, who replaced Chris Christie as transition chair over the weekend, says he’s committed to ensuring lobbyists are not involved with the transition effort.

Trump’s transition shared a copy of their 13-point ethics code, which “has been revised to ensure President-elect Trump’s ban on lobbyists is upheld at all levels of our transition landing teams,” said spokeswoman Jessica Ditto. The rules bar transition workers for involving themselves in matters on which they have lobbied within the last 12 months.

[The ethics rules that apply — and don’t apply — to Trump’s children]

This rule has prompted some swift changes on the transition staff. Joshua Pitcock, a senior Pence adviser, worked as a Washington lobbyist from 2013 until Monday, when he filed paperwork to terminate his status as a lobbyist. He had represented the state of Indiana.

Let’s recall the ethics policy for President Obama’s transition in 2008, touted as the most robust ever to apply to a president-elect’s team.

The 13 rules, covering three pages, prohibited transition personnel from involvement in matters related to a financial interest they had or on which they had lobbied in the last year. Current lobbyists had to abandon any outside work on matters related to their transition portfolio for the duration of the effort, plus a year afterward. (Trump’s post-transition lobbying ban is less stringent, covering only six months.) The rules explicitly banned bribes as well as gifts if they appeared intended to influence transition work. And workers pledged not to aid foreign governments or foreign political parties during the transition.

The Obama code built on George W. Bush’s 2000 transition ethics rules, which prohibited employees from using non-public information for private gain, barred them from lobbying for six months and disqualified them from transition work related to their financial interests.

Ethics experts say concerns about Trump turning the management of his far-flung real estate empire over to his children are complicated by their appointment — as well as that of his son-in-law — to the executive council of his transition committee.

[Donors and lobbyists are already shaping Trump’s ‘drain the swamp’ administration]

Trump has essentially empowered his family to have a hand in decisions about top appointees who could affect the family’s real estate empire. (After his election in 1976, Jimmy Carter set up elaborate arrangements to remove himself from the family peanut business, its management and knowledge of day to day decisions).

“The danger they face is they’re going to be accused of stacking the deck in favor of the Trump businesses,” said Richard Painter, chief White House ethics lawyer for President George W. Bush  from 2005 to 2007.

Michael Toner, who served as general counsel to the Bush-Cheney transition in 2000, recalled the 10 week post-election period as a time for setting broad ethical policy — and considering specific safeguards — that would set the tone for the incoming administration.

In 1992, Bill Clinton’s transition rules barred workers from having a hand in issues related to their financial interests and from lobbying on related matters for six months afterward. Four years earlier, George H. W. Bush required transition workers to pledge not to use inside information for profit.

There is no legal requirement that Trump sever ties to his business empire. The ethics laws that prevent other executive-branch officials from maintaining ties to companies that could benefit from their official actions does not apply to the president or the vice president.

Earlier this week a leading House Democrat, Rep. Elijah Cummings (D-Md.) called on Oversight and Government Reform Committee Chairman Jason Chaffetz (R-Utah) to launch an investigation of Trump’s financial arrangements “to ensure that he does not have any actual or perceived conflicts of interest.”

Tom Hamburger contributed to this report.