This design is a version of the Burgundy Cross with 16 stumps. A stump is a portion that extends from the bars that form the cross in the form of a cross. These are a symbolic representation of a cross made of tree trunks. According to tradition, this was the cross on which they crucified the apostle Saint Andrew. It was widely used in heraldry and therefore appears on many military flags of the Spanish empire.
Own work
BLUE ONE BANDERAS