The Ministry of Defence has failed in its battle to stop clothing retailers using the red, white and blue target symbol.
The roundel cannot be registered as a trademark on clothing
Arcadia Group, owners of Topshop, Dorothy Perkins and Burton, went to war with the MoD after it tried to register the roundel as a trademark for RAF-related clothing.
The high street fashion group argued the roundel was brought into the public domain by the Mod movement of the 1960s.
On Tuesday, the Patent Office told BBC News Online it had rejected the MoD's application.
However, the MoD has been given the sole rights to use the roundel, which appears on all RAF aircraft, on items other than clothing such as military hardware.
A spokeswoman for the MoD said they were now considering whether to appeal against the decision.
"We are naturally disappointed with the decision in respect of the suitability of the roundel as a trademark for RAF-related clothing," she said.
The target appears on all RAF aircraft
"However we are happy that the roundel has been protected as a trademark in respect of other goods and services."
Arcadia Group had enlisted the help of other clothing manufacturers, including The Lambretta Clothing Company, who have also used the motif on their products.
Making his decision John Macgillivray, for the Registrar the Comptroller-General, said the roundel "has been used since the 1960s to a significant degree as a decorative motif or emblem on articles of clothing and prior to the relevant date has been used by a number of different traders.
"It has, in particular, been associated with
a group of persons known as Mods and while its popularity has ebbed and flowed with fashion, clothing bearing the 'roundel' or 'target device' has remained available to the public."
He ordered the MoD to pay the Arcadia Group £1,900 costs.