English: rider (respondent)
Spanish: (compareciente) secundario, adicional
Definition (English):—
Definition (Spanish):—
Comments:This is a difficult term to research, given the prevalence of the term 'rider' in other contexts (contracts, insurance policies). Contrasting between the 'compareciente principal' (lead respondent) and 'compareciente secundario' (rider respondent) provides conceptual clarity.