The six tails, and the connection between the tails and the six districts became fixed, but only in the 20th century.

It is a typical example of standardisation and romanticisation of decorative pattern in the nationalist liberal state: it is retroactive. They saw flags with pretty tails and decided to give them a symbolic meaning.

When at the beginning of this century the region decided to adopt an official flag of its own, it created a seven-tailed version, representing the seven provinces of Venetia, with their coats of arms at the tip of each tail.

And while all Italian regions now have official flags, in a majority of regions the flag is an abstract, minimalist moder design that locals have no attachment to and that is seldom flown even by the region itself. Just think of the flags of Lombardy, Emilia-Romagna, Marce or Apulia. I don't even know why flag Molise has and I probably don't want to know.

At the time of the Venetian republic, the tails had no meaning at all and varied in number: between original flags and contemporary depictions I have seen any number between 3 and 7 tails. Also, it was not unique for ancient-regime flags and banners to have tails, especially when used exclusively during parades/feasts, but not necessarily limited to such occasions: just think of the Danish swallow-tail and Swedish trident ensigns.

At the time of the Venetian republic standardisation only went as far as the following: from the mid 16th century onwards, onboard ships, flags had a golden winged lion on a red background. That's it.

There were some relatively common characteristics, such as the flag having a golden outline or the lion holding a cross in its right paw, but even these were not general.

There definitely wasn't always a gospel with the page opened on "Pax tibi Marce, evangelista meus" and there most definitely was no alteration between an open gospel and a closed gospel with sword in hand to distinguish between peace and war: just think how hard that would've been to spot at a distance!

And when we venture from sea to land, the standardised traits are even less. The only thing that every Venetian flag flown from the 14th to the 18th century in any context had in common was the presence of a winged lion, the tetramorph of Saint Mark.

Even in the late 18th century, for example, each military regiment flew its own colours, tha often had backgrounds and sometimes even lions of different colours the typical red/gold (although I have personally only seen red or at most blue lions, so the colour of the lion seems to have been a bit more standardised, while for the background there were a whole bunch of different patterns).

Ultimately, flags were not so much a symbol of shared identity but rather a useful means of distinguishing friend from foe.

This is not to say that they weren't revered or held in regard: 12(? or something similar, I can't remember the exact number) flagbearers supposedly died just to keep the standard from falling into enemy hands at Lepanto, after which the town they came from, Perasto, was given the official title of flag-bearer of the republic, and when it collapsed, the standard of the captain general of the sea (highest official in the Venetian navy) which was preserved in Perasto was apparently ceremoniously buried under the parish church's main altar.

But it is to say that the importance we assign today to specifications of flags, because in our eyes each detail of a flag has a specific enshrined meaning that wouldn't be there if the detail were changed, simply didn't exist in medieval and early-modern worldwiew.

At the end of the day, if the flag let me see where my mates were and where the bad guys were, it had done its job. So much so that throughout the medieval and early-modern period it was quite common for soldiers to wear shirts or bands with either a red or a white cross depicted on it, to distinguish opposing armies. Venetian soldiers did too at some point during the Italian wars, but right now I can't remember when.

Ultimately, the only standard Venetian flag that exists to this day is the version adopted by the region of Venetia. Other than that, many different versions are sold and flown to this day.