Sets (collections without duplicates) must be enclosed by < and > characters. E.g. <1,2,3>, <#10:3,#10:4> and <(name:"Luca")>. There is a special case when use LINKSET type reported in detail in Special use of LINKSET types section. Before rel.15 SET type was stored as a list (see upon).
From binary protocol docs:
Sets (collections without duplicates) must be enclosed by < and > characters. E.g. <1,2,3>, <#10:3,#10:4> and <(name:"Luca")>. There is a special case when use LINKSET type reported in detail in Special use of LINKSET types section. Before rel.15 SET type was stored as a list (see upon).