Op Corporate Medal:
The medal with rosette was awarded for one day's service within 35° and 60° South latitude or for at least one operational sortie south of Ascension Island, between 2 April and 14 June 1982 (April 2 being the date of the Argentine invasion, June 14 being the date of Argentine surrender). This, generally, denoted service in the combat zone. Where the rosette was worn on the ribbon, this was both with the medal and on the ribbon bar.
The medal without rosette was awarded for 30 days continuous or accumulated service between 7° and 60° South latitude between 2 April and 14 June 1982 (completing no later than 12 July 1982). As a result of the 2012 Independent Medal Review conducted by Sir John Holmes, from 1 October 2014 the qualifying period for the medal without rosette was extended to 21 October 1982, the date modifications were completed to RAF Stanley airfield allowing operation of RAF Phantoms.
The rosette remains an unusual feature for a British medal and was used partly for economy and speed of manufacture, and also as otherwise fewer than two hundred medals would have been issued to the Royal Air Force. While for other arms the vast majority of the medals were issued with a rosette, over 90% of the medals issued to the Royal Air Force are without the rosette, with the recipients mainly stationed on Ascension Island, some 3,300 nmi (6,100 km) north of the Falkland Islands and the war zone.
Yup, full of shite
This is basically the same system as we used for the Afghanistan and Iraq/Syria OSMs to identify those who got it with a clasp isn't it? The criteria in all cases seems to be about where you were rather than what you did.