The instruction to camouflage cars is one of 22 tips on how to avoid drones, listed on a document left behind by the Islamic extremists as they fled northern Mali from a French military intervention last month. A Xeroxed copy of the document, which was first published on a jihadist forum two years ago, was found by The Associated Press in a manila envelope on the floor of a building here occupied by al-Qaida of the Islamic Maghreb.

The tipsheet reflects how al-Qaida’s chapter in North Africa anticipated a military intervention that would make use of drones, as the battleground in the war on terror worldwide is shifting from boots on the ground to unmanned planes in the air. The presence of the document in Mali, first authored by a Yemeni, also shows the coordination between al-Qaida chapters, which security experts have called a source of increasing concern.

“This new document… shows we are no longer dealing with an isolated local problem, but with an enemy which is reaching across continents to share advice,” said Bruce Riedel, a 30-year veteran of the CIA, now the director of the Intelligence Project at the Brookings Institution.

The tips in the document range from the broad (No. 7, hide from being directly or indirectly spotted, especially at night) to the specific (No 18, formation of fake gatherings, for example by using dolls and statues placed outside false ditches to mislead the enemy.)