The national flag of Switzerland (; ; ; ) displays a white cross in the centre of a square red field. The white cross is known as the Swiss cross or the federal cross. Its arms are equilateral, and their ratio of length to width is 7:6. The size of the cross in relation to the field was set in 2017 as 5:8. The white cross has been used as the field sign (attached to the clothing of combatants and to the cantonal war flags in the form of strips of linen) of the Old Swiss Confederacy since its formation in the late 13th or early 14th century. Its symbolism was described by the Swiss Federal Council in 1889 as representing "at the same the Christian cross symbol and the field sign of the Old Confederacy". As a national ensign, it was first used during the Napoleonic Wars by general Niklaus Franz von Bachmann, and as regimental flag of all cantonal troops from 1841. The federal coat of arms (eidgenössisches Wappen) was defined in 1815 for the Restored Confederacy as the white-on-red Swiss cross in a heraldic shield. The current design was used together with a cross composed of five squares until 1889, when its dimensions were officially set. The civil and state ensign of Switzerland, used by Swiss ships, boats and non-governmental bodies, is rectangular in shape and has the more common proportions of 2:3. The Swiss flag is the only square national flag in the world. The emblem of the Red Cross is the Swiss flag with switched colours. Design According to the 2017 flag law (SR 232.21), "the Swiss flag shows a Swiss cross on a square background". Special provisions are made for the naval ensign and for civil aircraft identification. The Swiss cross is defined as "a white, upright, free-standing cross depicted against a red background, whose arms, which are all of equal size, are one-sixth longer than they are wide." Swiss Standard German consistently uses (cognate with vane) rather than the term used for national flags in Germany. The name of the flag of the Swiss Confederation is a nominal compound, . The flag is emblazoned in English as, "Gules, a cross coupée argent." Proportions While the proportions of the cross have been fixed since 1889, the size of the cross relative to the flag (the width of the margin separating the cross couped from