(CNN) -- Word that all passengers on flights within and to the United States are now being checked against government watch lists may have travelers wondering how they were being screened up until this point.
Tuesday's announcement by the Department of Homeland Security, which said the milestone fulfills a key 9/11 Commission recommendation, may have also made fliers curious about the status of other mandates from the panel.
In July, the Department of Homeland Security released a report spelling out the government's progress in implementing the directives almost a decade after the September 11, 2001, attacks.
It shows that work continues to fulfill some of the mandates, which fall under four major categories relating to aviation security:
Recommendation: Improve airline passenger prescreening
This is where Secure Flight, the government-run program that is now vetting passengers before they receive their boarding passes, comes in. It replaces a more ad hoc system run by the carriers.
"Prior to Secure Flight, the airlines themselves were responsible for matching all of their passengers against the watch lists, so each airline had their own system for doing that," said Greg Soule, a spokesman for the Transportation Security Administration.
"Secure Flight takes the passenger watch list matching process away from the airlines and puts it all in one program under TSA, so it is a more consistent process across the board."
Passengers have to give their full name, date of birth and gender under Secure Flight. Previously, they had to supply only their names.
All domestic and international air carriers that fly within the United States, or in or out of the United States, are now participating in Secure Flight, Soule said.
Recommendation: Improve airline passenger explosives screening
Measures to fulfill this directive include explosives trace detection technology, which can detect tiny amounts of explosive materials either on passengers or their baggage; bomb-sniffing dogs; and a behavior detection program, where specially trained officers look for passengers showing high levels of stress or fear.
Travelers will also see more body scanners. More than 400 advanced imaging technology machines are already in place in about 70 airports, and the TSA plans to have almost 1,000 in airports nationwide by the end of 2011, Soule said.
"We're always looking to enhance our technology to stay ahead of the ever-evolving threat," he added.
Recommendation: Improve checked bag and cargo screening
One hundred percent of all checked bags are screened for explosives, Soule said.
But the recent terror scare involving packages in cargo planes has put a new spotlight on the possible danger lurking below passengers' feet.
One hundred percent of cargo flown on passenger planes that take off from U.S. airports is screened for explosives as part of a congressional mandate that was fulfilled in August.
But it's a different story for U.S.-bound planes that take off in other parts of the world. At this point, about two-thirds of the cargo on international inbound passenger air carriers is screened, Soule said.
"TSA is making substantial progress toward meeting the 100 percent mark and has stated that industry would attain that goal no later than 2013," he said.
"High-risk" cargo is not permitted on passenger aircraft, he added, but he declined to specify what that might be for security reasons.
The TSA requires enhanced screening of packages on all cargo aircraft that are determined to be higher risk, based on intelligence, manifest and shipper information, Soule said.
Recommendation: Develop a risk-based plan for transportation security
In June, the TSA submitted the Transportation Sector Security Risk Assessment (TSSRA) to Congress.
The report examined the potential threat, vulnerabilities and effects of a terrorist attack involving the country's transportation system and ways to prevent or mitigate it.
The TSSRA is provided to Congress annually.