Here are three versions of the "Sold Out of Service" opposing broad arrows. The broad arrow, as you may know, is the symbol of the British War Department. The overall meaning of this marking is that the weapon was released from Military service, or "Sold Out of Service". Often they were then sold to the public, or to rifle clubs. This marking is generally seen on the right and/or left side of the action body, knoxform and often on stamped into the wood of the weapon's buttstock.

Opposing broad arrows, touching.

Opposing broad arrows, not touching.

Opposing broad arrows with "S". The "S" denotes the weapon was "Safe" or "Serviceable", and did not need to be reproofed if sold in England.

Here's one commonly found on Mark IV Martini-Henry Rifles which saw service in India. "F A" stands for Firozpur Arsenal. Firozpur is located in the south-west portion of Punjab.

Sold out of service from the Kirkee, India Arsenal. Commonly seen on M-H Mark IV's.