Not mentioned in the video: Roman citizens (males) were given the right to wear an iron ring of citizenship. Different classes (equestrian, senatorial, etc) might have a specific design on them but it was still pretty basic. Two issues were that the ring was not required to be worn so not everyone did, and of course one could be stolen or counterfeited so you couldn’t take it as reliable proof of anything.
But it’s at least somewhat related to the topic.
“Hold Me Or I Will Run!” Roman Slave Collars Came With A Warning
https://www.ancient-origins.net/history-ancient-traditions/roman-slave-collar-0015780
The Horrible Life of an Average Roman Empire Slave
The Infographics Show
https://www.youtube.com/watch?v=jsmWI1TnfDA&t=10
Shackled Skeleton Reflects Brutal Reality of Slavery in Roman Britain
https://www.smithsonianmag.com/smart-news/why-was-man-buried-shackles-roman-britain-180977904/
What Did Roman Slaves Wear?
https://www.reference.com/history-geography/did-roman-slaves-wear-14df366b96f08141