SS Collar

Robert, 2nd Lord Hungerford was buried at Salisbury Cathedral, and his memorial clearly shows an “SS collar” on his effigy.
“Collars” have long been used as insignia to symbolise a rank, a relationship, an award or honour or some other form membership (eg member of a lodge).  They have taken many forms over the centuries and some still exist today, for example mayoral chains and gorgets.