
Insignia (the plural of Latin insigne: emblem, symbol) is a symbol or token of personal power, status or office, or of an official body of government or jurisdiction. Insignia are especially used as an emblem of a specific or general authority.
Typical examples of insignia are: crowns, flags of a country or state, regimental banners, coats of arms, seals, monograms, ensigns, corporate logos, shop signs, roundels, badges.
Since the 15th century the terms of emblem (emblema) and emblematura belong to the vocabulary of architecture. They mean an iconic painted, drawn, or sculptural representation of a concept affixed to buildings; and belong — like the inscriptions — to the architectural ornaments.
From the Renaissance onwards emblems were seen as related to Egyptian hieroglyphics and considered as being a secret iconic language. Emblems belonged to the rediscovered knowledge of antiquity.
A specific social group where ancient symbols play an important role is the freemasonry. From the early 18th century onwards, many exposés have been written claiming to reveal these signs to the uninitiated.
A tradition originating in mediaeval chivalry is heraldry. The painting of coats of arms is subject to strict rules. Nevertheless heraldry has long been a part of decorative painting. Below a brief outline of some basic principles & rules:
The focus of heraldry is the armorial achievement, or the coat of arms, the central element of which is the escutcheon or shield. In general, the shape of the shield employed in a coat of arms is irrelevant, because the fashion for the shield-shapes employed in heraldic art has evolved through the centuries.

Tinctures are the colours used in heraldry. Since heraldry is essentially a system of identification, the most important convention of heraldry is the rule of tincture.
The names used in English blazon for the colours and metals come mainly from French and include Or (gold), Argent (white), Azure (blue), Gules (red), Sable (black), Vert (green), and Purpure (purple). In heraldic books with black and white illustrations they were often indicated in shorthand.
Certain patterns called "furs" can appear in a coat of arms, though they are (rather arbitrarily) defined as tinctures, not patterns. The two common furs are ermine and vair.
In the early days of heraldry, very simple bold rectilinear shapes were painted on shields. These could be easily recognized at a long distance and could be easily remembered. As more complicated shields came into use, these bold shapes were set apart in a separate class as the "honorable ordinaries."
A charge is any object or figure placed on a heraldic shield or on any other object of an armorial composition. Any object found in nature or technology may appear as a heraldic charge in armory. Charges can be animals, objects, or geometric shapes. Apart from the ordinaries, the most frequent charges are the cross - with its hundreds of variations - and the lion and eagle.
Marshalling is the art of correctly arranging armorial bearings. Two or more coats of arms are often combined in one shield to express inheritance, claims to property, or the occupation of an office. A shield may be subdivided into what is referred to as division.
In English the word "crest" is commonly used to refer to a coat of arms - an entire heraldic achievement. The technical use of the heraldic term crest refers to just one component of a complete ensemble. The crest rests on top of a helmet which itself rests on the most important part of the achievement: the shield.
The crest has evolved from the three-dimensional figure placed on the top of the mounted knights' helms as a further means of identification.
The crest is usually found on a wreath of twisted cloth and sometimes within a coronet. When the helm and crest are shown, they are usually accompanied by a mantling. This was originally a cloth worn over the back of the helmet as partial protection against heating by sunlight. Today it takes the form of a stylized cloak hanging from the helmet. The mantling is sometimes conventionally depicted with a ragged edge, as if damaged in combat.
In most heraldic traditions a woman does display neither a crest nor a shield. As women did not go to war, they did not bear a shield, instead, women's coats of arms were shown on a lozenge—a rhombus standing on one of its acute corners.
Non-combatant clergy also have used the lozenge and the cartouche (an oval) instead of a shield. They also refrained from displaying a helm or crest in their heraldic achievements. Members of the clergy did however display appropriate head wear, sometimes signifying their rank. This ranges from a small crowned, wide brimmed hat, to - in the case of Papal arms - an elaborate triple crown known as a tiara.
"Supporters" sometimes flank the shield. These can have the shape of knights, or of animals, like lions or boars. Only Peers are entitled to the use of supporters.
An armorial motto is a phrase or collection of words intended to describe the motivation or intention of the armigerous person or corporation. Mottoes are generally changed at will and do not make up an integral part of the armorial achievement. Mottoes can typically be found on a scroll under the shield.
Though heraldry is more than 900 years old, it is still very much in use. Many cities and towns in Europe and around the world still make use of arms.
Personal heraldry, both legally protected and lawfully assumed, has continued to be used around the world. Heraldic societies strive to promote education and understanding about the subject. And painted coats of arms are stil popular, either as a stand-alone subject or as part of a more elaborate decorative scheme.