Deciphering a medal index card

[kumalase]

I have just found my grandfathers war medal which gave his regiment and number, and so located his medal index card.

As well as showing the details I already had,  Harry Smith, northumberland fusiliers number 12222. It also shows a following entry for the royal fusiliers with a service number of GS/93267. 

Can anyone explain what the GS stands for?   Also as the details re northumberland fusiliers are on the medal I am assuming this is the regiment he was serving with at the end of the war. Am I right in thinking he initially was in the royal fusiliers and was transferred at some later date, and would this be because he was injured and then when recovered was sent where needed.

Also would the fact he only received victory and British medals indicate he enlisted after 1816.

I am new to this and am therefore possibly asking questions which are obvious, but any help is appreciated.

Thank you

[Buzancy18]

He was in the Northumberland Fusiliers and then transfered to the Royal Fusiliers. GS is General Service.
Buzancy18

[jds1949]

The fact that he had no entitlement to the 1914 or 1915 Star should mean that he did not see service in an active theatre of war before 1916 - but that doesn't necessarily mean that he did not enlist before 1916. He could have been in training or deployed on non-combatant duties in the UK prior to being posted to France or wherever.

jds1949

[forester]

It may be worth pursuing a link between Northumberland Fusiliers men transferred into the 23rd and 24th Battalions of the Royal Fusiliers, probably around the middle of 1918.

Phil

[kumalase]

Thank you all for your prompt replies.  It's is greatly appreciated and I will certainly follow up on your suggestions.

Thanks again