, to circumvent the limitations of the South African Defence Act (Act No 13 of 1912), only volunteers were recruited and they were subject to an oath on induction whereby they consented to being deployed anywhere in Africa, this being a pre-requisite for acceptance into the Union forces. Men who attested under these terms were entitled to wear the distinct insignia of the Mobile Field Force, a red / orange shoulder strap which was to become known as the "Red Tab". The Defence Act was later amended.