Operation Anvil (Mau Mau Uprising) the reserves. The "Grey" grade was made up of prisoners believed to be passive Mau Mau sympatherisers though for whom strong evidence suggesting their true loyalties was lacking. The last category, "Black", was reserved for detainees identified by the hooded informers or the Special Branch of the Kenya Police as potentially violent insurgents or terrorists. A few may have been prosecuted by the government, but most were funneled through the "Pipeline", a system of work camps, decreasing in brutality until an individual was "re-educated" and deemed safe to release on a native reserve. Operation Anvil (Mau Mau Uprising) Operation Anvil
Mau Mau Uprising Mau", claim it was an anagram of "Uma Uma" (which means "get out get out") and was a military codeword based on a secret language-game Kikuyu boys used to play at the time of their circumcision. Majdalany goes on to state that the British simply used the name as a label for the Kikuyu ethnic community without assigning any specific definition. As the movement progressed, a Swahili backronym was adopted: "Mzungu Aende Ulaya, Mwafrika Apate Uhuru" meaning "Let the foreigner go back abroad, let the African regain independence". J.M. Kariuki, a member of Mau Mau who was detained during the