In his Tratado de las Armas, Diego de Valera (1412-1488) devotes a section to the various types of banners that he believes should be used, and who could use them. It's possible that what he describes was not taken literally but I think it's still an interesting reference, and more so in absence of more complete studies.
The images are my versions of the ones accompanying the text and could contain errors. In particular, I have added an heraldic design to help distinguish those banners that would bear arms from those that arms that would have mottoes or emblems or simply the corresponding colours (in red). The flag names are only partially translated because of my lack of knowledge of corresponding terms - if in doubt trust the Spanish name.
| Belongs to | Shape | Possible aspect | |
| Vandera real - royal flag | Reyes | Longer than it's wide | |
| Vandera - flag | Dukes, marquises, counts, viscounts, admirals and barons; and their firstborn. | Square | ![]() |
| Vandera - flag | Other descendants of those above | Square with a tail | ![]() |
| Pendón | Orders (Santiago, Calatrava, Alcántara, Sant Iohan) | ![]() |
|
| Palón | Cities, villages or communities | ![]() |
|
| Grinpola | Knight or gentleman, over his tomb, and in the lists, when having to fight or use arms. | ![]() |
|
| Guitón | Emperors or kings near their person when going with a host; or the constables and captains general of their hosts. | ||
| Estandarte - standard | Any knight or gentle man or captain charged with governing people of arms | ![]() |
|
| Gonfalón | Captains of few people | Smaller standard | ![]() |
In times of war kings must carry flag, standard and guitón. The flags are not to be unfurled until the time of combat, in view of the enemy, so it's convenient to carry a standard.
The standard, guitón or gonfalón must not have arms on them but "only motto or enblem, or diversity of colours".
Tratado de las Armas, by Diego de Valera. Published in "Prosistas Castellanos del siglo XV" ed. Mario Penna. Atlas, Madrid 1959, pp. 132-133.
Medieval Flags and Banners has alternative descriptions and illustrations, from various centuries and countries.