When the gun is fired the marking theoretically leaves a serial number on the primer encased in the spent cartridge.

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Key Stage 2 test markers, who are practising or retired teachers, receive thorough training and undergo a number of quality checks through the marking process.

BBC: Head teachers complain of 'erratic' Sats marking

It has promised longer sentences for people who carry guns illegally and new electronic marking of state-owned weapons in the hope of cutting the number of Kalashnikovs seeping into the black market, where they are bought more cheaply than anywhere else in the world.

ECONOMIST: Guns in Africa

However that number was up 30 percent from the same time last year, marking the worst quarter since 2011.

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Internet analysts at Nielsen Online reported that the number of unique visitors in Britain visiting Facebook fell in January, marking the first time it has seen a decline in the key metric in 17 months.

FORBES: Facebook Falters In Europe

Reaching its highest level since March 2010, the number of planned layoffs was up 32% from January and 20% from February 2010, marking the first year-over-year increase in monthly job cuts since mid-2009.

FORBES: Job Cuts Hit An 11-Month High Of 50,702