An excerpt of "Barack Obama: The Story," by David Maraniss, an associate editor at The Washington Post, says the group called themselves the "Choom Gang." Choom is a verb meaning to smoke marijuana, an excerpt of the book says, the Post reported.
"As a member of the Choom Gang," Maraniss wrote, "Barry Obama was known for starting a few pot-smoking trends."
One of those was "Total Absorption" or "TA."
"TA was the opposite of Bill Clinton's claim that as a Rhodes scholar at Oxford he smoked dope but never inhaled," Maraniss wrote.
For exhaling prematurely while with the Choom Gang, "you were assessed a penalty and your turn was skipped the next time the joint came around."
The book said Obama -- who has previously acknowledged having smoked pot in his youth -- helped popularize "roof hits."
"When they were chooming in a car all the windows had to be rolled up so no smoke blew out and went to waste; when the pot was gone, they tilted their heads back and sucked in the last bit of smoke from the ceiling," the book said.
Maraniss wrote Obama was known for "interceptions."
"When a joint was making the rounds, he often elbowed his way in, out of turn, shouted 'Intercepted!' and took an extra hit."