Which term designates an item used to identify a slave for sale?

The term that designates an item used to identify a slave for sale is "titulus." In ancient Rome, a titulus was a written notice that was often attached to a slave's neck or was visibly displayed with them, detailing their price and any pertinent information about their capabilities or background. This practice was crucial for potential buyers, as it provided essential details in a highly transactional environment.

The other options refer to different concepts in Roman culture. A sportula refers to a small gift or gratuity often given by wealthy patrons to their clients. The pilleus was a cap that symbolized freedom in Roman culture, typically worn by freedmen. A vicarius was a term used for a deputy or a substitute, particularly in administrative contexts but not related to the sale of slaves. Understanding these distinctions is essential for grasping the social and economic structures of ancient Rome.