How the Trump administration plans to implement its limited travel ban The ban could go into effect 72 hours after the Supreme Court ruling.

 -- The president’s limited travel ban is expected to go into effect at 8 p.m. ET today, according to a Department of Homeland Security official.

The Supreme Court said the ban could go forward, with an exception for people who have "any bona fide relationship with a person or entity in the United States." Lawyers from the Departments of Justice, State and Homeland Security worked through Wednesday to define a "bona fide relationship" and to make sure the implementation of the order would be in compliance with the ruling.

After President Trump signed his first order in January restricting travel, which became effective immediately, there was widespread confusion over who was permitted to enter the country. Visa holders at airports were detained, and immigration lawyers scrambled to get them released and admitted into the country.

Similar confusion is not expected today in part because the administration decided to delay implementation for 72 hours to allow for preparations.

Anyone from one of the six affected countries who has already been issued a visa will be allowed to enter, according to a State Department official. No visas have been canceled by the ruling, and any refugee who has been scheduled to be resettled before July 6 will be allowed to enter.

The Associated Press obtained a cable sent to all U.S. embassies and consulates late on Wednesday that detailed the new rules, including the definition of "bona fide relationship." The contents of the cable as reported by the AP were independently confirmed by ABC News.

Under the new guidance, visa applicants from the six countries - Syria, Sudan, Somalia, Libya, Iran and Yemen - must prove a relationship with a parent, spouse, child, adult son or daughter, son-in-law, daughter-in-law or sibling already in the United States.

Homeland Security will work with its component agencies, primarily Customs and Border Protection, which screens travelers and inspects travel documents, and Citizenship and Immigration Services, which has a part in refugee screening, on procedures for implementation, according to a DHS official.

No visa interviews have been canceled either. That means that the State Department could have issued visas through Thursday to individuals from the six affected countries without asking them to prove a "bona fide relationship."

After the order goes into effect, consular officers responsible for granting visas for citizens of the six countries will begin asking applicants to prove a "bona fide relationship."

The State Department is still determining what will happen to refugees scheduled for resettlement after July 6.

State Department spokeswoman Heather Nauert said Tuesday, "We want travelers or prospective travelers to know exactly what they may or may not be facing, so we'll get that information out."

While the White House may avoid the airport turmoil from before, there will likely still be legal disarray, with lawsuits about that key "bona fide" criterion.

ABC News' Justin Fishel contributed to this report.