Most towers and baileys are defensive, protecting defenders from attackers. This keep tower and bailey is used to protect everyone else from what is within.
Some time magic users are less magical than one expects.
The district gets its name by the good sized walls that are painted a bright blue that mark the magic district. That wall is watched by the Witchhunter guard.
Helioglyph (his magical name) is a Talismonger, a maker of charms, talismans, holy items, and so on. This is the place where those seeking fine craftsmanship and good symbolism come. If you are looking for enchanted items, go elsewhere.
The size and number of knots in hair, tied around neck, or hanging from belt could signify family, importance, worship, guild affiliations. Being able to translate the meaning of the size and placement of knots can give you a a large understanding of who somebody is.
May be used in a more barbaric society. Where in cities peoples clothes and crests show who they are, barbarians have no need for this so use knots.