As stated in the episode, the Armorer's Faith refers to a quote from the three-act play "Major Barbara (1941)" by George Bernard Shaw. The quote "To give arms to all men who offer an honest price for them without respect of persons or principles and to all nations, all faiths, all causes, and crimes. All have the right to fight. None have the right to judge."The corollary to the statement is "to break the faith is to take a side.
And for dealers such as us, that means certain death."
The Los Zetas are a Mexican criminal syndicate, regarded as the most dangerous of the country's drug cartels. Its original membership was composed of former Mexican Army personnel, who served as assassins or the enforcement arm of the Gulf Cartel, until its high-ranking leadership decided to break off and start a rival cartel. Its name is derived from the Federal Judicial Police Code for commanding officers whose jurisdiction lies in the more urban areas of the country (Zeta is the Spanish designation for the letter Z). The group's activities lies in drug and sex trafficking as well as protection and gun running rackets, and they have used violent means to consolidate control over their domain: beheadings, torture, assassinations, extortion, kidnappings and indiscriminate murder have all been used toward this end.
A Surveillance Detection Route, or SDR, is a means to determine if one is being followed by a Hostile Intelligence Service.
With respect to the Security Services, MI5 is Britain's Domestic Intelligence Service, while MI6 is the Foreign Intelligence Service (ex. James Bond).
In the opening scenes. The banner informs us Blackbush airport London. When in fact it's spelled Blackbushe airport.