Heraldry
WikiPedia description
Heraldry is a discipline relating to the design, display and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, rank and pedigree.12 Armory, the best-known branch of heraldry, concerns the design and transmission of the heraldic achievement. The achievement, or armorial bearings usually includes a coat of arms on a shield, helmet and crest, together with any accompanying devices, such as supporters, badges, heraldic banners and mottoes.3
Although the use of various devices to signify individuals and groups goes back to antiquity, both the form and use of such devices varied widely, as the concept of regular, hereditary designs, constituting the distinguishing feature of heraldry, did not develop until the High Middle Ages.4 It is often claimed that the use of helmets with face guards during this period made it difficult to recognize one's commanders in the field when large armies gathered together for extended periods, necessitating the development of heraldry as a symbolic language, but there is little support for this view.45 source: https://en.wikipedia.org/wiki/Heraldry
NOTES
Historically, people didn't necessarily know how to read or write. The development of these skills is only relatively recent, indeed within the western world; there are some remarks about the important role christianity played as a consequence of widespread distribution and teachings of the Bible; which was often, in-turn, the only book and teachings of how to read a book provided to many broadly disadvanged persons.
The implication or consequence becoming; the common use of pictorially provided signs and symbols that had particular meanings; for particular communities at particular times, etc.
These sorts of visual representations involved both the images and structure upon which objects were reprsented alongside colours - noting that some colours were very expensive to produce, obtain and/or use; indeed some, it is said, were exclusively provided only to few.
Some insights were ganished in-particular; due to the consequence of my studies of the history of the banking system, which happens to lead to londinium; which is the area associated with my surname. Which of course, sparked my interest; notwithstanding earlier studies with respect to IndigenousLanguages...
Therein; with respect to both cases, more study is required; but with respect to what i learned about the circumstances of england around 1000AD Seems to suggest; that what may have been the case; is that, these signs, ensigna and other symbols and related systems were used to support the concept of 'common sense' at a time where there was not one unifying spoken, written and readable language format - akin to the english vocabulary of today.
One of the many gateways into this field of knowledge; is considered to be Heraldry.
Folder of Resources: https://drive.google.com/drive/folders/1BT4R0hD2CDFydMhqkZpHE35AyfY43shn