Starting today, anyone apprehended in Philadelphia with about an ounce of marijuana or less could see the charges downgraded to a summary offense.

Take a class, pay a $200 fine and any record would be expunged - that's what is likely to happen now in several thousand cases a year, said Deputy District Attorney Ed McCann.

Just don't expect hands-off treatment by police, if you're caught with a small amount of marijuana, defined as 30 grams or less.

"You're still arrested, you're still brought in, you're still fingerprinted, you're still given a prelim," said Tasha Jamerson, spokeswoman for the District Attorney's Office.

Only at the preliminary arraignment are procedures changing, as many cases will be "diverted" from misdemeanor charges, said McCann.

That won't be automatic either.

Some reasons for withholding leniency for pot possession include attempting to sell, being caught during a serious crime, and having a criminal record, McCann said.

To qualify for diverting, "we're talking about this offense being a standalone offense, or this being the most serious charge," he said.

"It should be a tremendous savings to the court system," greatly reducing police testimony, public defenders and documentation, he said.

The change in policy was announced in April by new District Attorney Seth Williams.

A vocal opponent has been his predecessor, Lynne M. Abraham, who has said, " 'Welcome to Philadelphia, Light Up a Joint' may just be our new slogan."

"Local gangs and marijuana growers everywhere are positively overjoyed," she has said.

McCann sees it differently. "It's a reasonable response to a large number of cases that don't have to be . . . clogging up the court system," he said.