The flag was adopted officially on 29 October 1953 based on a design in use from 1889. In the central shield, the stars symbolize the municipalities of the state, the eagle represents the productive forces, the key symbolizes the strategic position of the state in the south, the anchor refers to the ocean that bathes the state, and the date 17 November 1889 is that of the adoption of the republican regime. The branches correspond to the coffee plant and the phrygian cap also symbolizes the republican regime.
At www.senado.gov.br/web/senador/casmalda/Frbander.htm is the text of law no. 975 of 29 October 1953, "Reestablishing the Flag of the State of Santa Catarina and Giving It New Composition," article 2: The flag ... will have the following composition: (a) 3 stripes of equal width, the outer two red and the center white; (b) superimposed, a light green [verde claro, footnoted to mean verde-limão, or lime green] lozenge, whose extremities do not reach the stripes; (c) the lozenge will have the arms of the state on the center.Article 2 of Decree No 605 of 19 February 1954 (summarizing here rather than quoting):
- dimensions 11 units fly by 8 units hoist
- vertices of the lozenge to lie one unit from the edges of the flag
- the arms will be circumscribed by an imaginary circle of radius 2.75 units
- the crossing of the key and the anchor in the arms to lie at the center of the flag
- the vertices of the star to fall on the circumference of an imaginary circle of radius 0.5 units, centered 0.375 units above the crossing of the key and the anchor
- the red stripes to be encarnadas and the lozenge verde claro
The arms are the same as those adopted in 1899.