The Exchange of Writs

Within the city of Vendrick's Fall the economy is highly dependent on the various guilds which act as the central authority of the city. During the Fall harvest festival, The Exchange of Writs acts as an opening ceremony of sorts, where the the outlying farmers and hunters are celebrated with gifts from the various guilds, each guild has there own Writs which act as a favor from that guild. The accomplishments and successes of the hardy folks that live beyond the city walls are praised. The Writs are meant as gifts for those that don't benefit from the safety of the city walls, but who's work is vital to the continued success of the city.
Every year the Writs are unique and vary from guild to guild, and it's common practice for the Writs to be highly decorative and brightly colored, but they all have the official mark of the guild which it originated from which makes them a legitimate form of tender accepted by the guild from which it originated.
The exchange of Writs is celebrated, and it's common for the people gifted with Writs, to exchange them further, as everyone tries to trade the Writs they have for whichever Writs they feel they might need, as the needs of farmers, and hunters, and fishermen are all very different, and they may not receive the specific Writs they might be looking for. 
Whenever a Writ is exchanged during the harvest  festival, a show is made of tearing up the brightly colored paper and throwing it into the air as a celebratory confetti.
Any Writs not exchanged by the end of the festival technically lose their value, however there are a number of collectors within the city who are happy to exchange money for expired Writs and pride themselves on the diversity of Writs they've collected, and compare and contrasting the different Writs year to year.