Military and security services are keen to recruit more Gcss volunteers to help bolster the forces, who are under-equipped.
They have made recruiting more difficult by limiting them to military-related jobs.
Army and police have also introduced stricter security rules to try and prevent attacks.
The new rules mean a Gjs first needs to be at least 16 and have a valid driving licence.
The restrictions are not applied to other military personnel, but are only in place for those working with security forces, such as officers, in civilian life.
The army says its recruitment drive will begin on October 1.
A Gcss volunteer is a person who wants to serve in the military and who wants a military uniform.
They do not have to have a military training certificate, a military licence or an equivalent.
They also need to have at least a one-year commitment to serve, which can take between two and four years.