The Territorial Force (T.F.) were not liable for overseas service. 
In time of national emergency, the troops of the regular army would leave for service overseas, and in their place, responsibility for Home Defence would fall to the men of the Territorial Force.
The Government however, realised that with the larger conscription-generated armies amassing on the continent, that should a war come and the Army be called to Europe, that a reserve would be needed to supplement them and provide a pool of trained men to go and fight. Thus, in 1912, The "Imperial Service Obligation" was introduced for the T.F. 
By signing Army Form E.624, the T.F. soldier agreed to “subject himself to liability to serve in any place outside the United Kingdom in the event of National emergency.”  It was a voluntary undertaking on the part of the Territorial Soldier, and in nearly every case, entire units signed-up to a man, to serve overseas if the need arose.
In compensation, the volunteer received a white metal brooch bearing the words “IMPERIAL SERVICE” which he could wear above the right hand pocket of his service dress jacket, just like Sergeant Sydney Green, above, of 4th Suffolk whose badge can be seen above.

To those readers of the Suffolk Regimental Gazette, the July 1914 edition gave no indication that there was trouble in the air. 
The impending doom that was to follow Austria’s declaration of war on Serbia, was not mentioned anywhere in it's 19 pages. The news was instead, far more jolly. 
The 1st Battalion had recently returned from Khartoum and currently had a detachment in Cyprus; where they were winning several boxing matches against rival regiments. The 2nd Battalion still remained at the Curragh in Ireland and the 3rd (Special Reserve) Battalion were recovering after an exhausting march through the county in June. From Bury, they had proceeded to Landguard Fort at Felixstowe on a specially chartered train for musketry training. From here they marched back to Bury via Ipswich and Stowmarket, attending several events on the way.
The 4th Battalion were preparing for their annual camp - due to take place at South Denes, Great Yarmouth. Special trains had been arranged to get the different Company’s there from across the county and local Drill Halls were getting the men’s equipment out, checking and re-checking their rifles, making ready for the three-week camp. 
It would be the last annual camp of the 4th Battalion for ten years.