Table 1.

Variables and operational definitions.

Variable	Operational definition
Sexual services provided	Sexual service provision communicationsa refer to the types of sexual acts that the person offers within their advertisement.
Sexual service restrictions	Restriction communications refer to the sexual services that the person advertising reports being unwilling to engage in during the provision of sexual services.
Health	Health communications were operationalized into two categories: (1) communications that specifically speak to health-related practices that could be considered protective or nonprotective for health (eg, nonsmoker, drug use, condom use) and (2) presence or absence of specific health issues (eg, HIVb, sexually transmitted infections).
Safety and security	Safety and security communications refer to factors associated with positively or negatively affecting people’s physical, emotional, and financial well-being including their privacy. Specific categories for extraction included (1) location where sexual services provided, (2) instructions for clients on how to prepare for the encounter, (3) security measures taken before encounter including screening processes, (4) security measures during the encounter, and (5) facial photo details.
Demographic characteristics	Demographic communications refer to salient information about the “structure” of the population and included age, ethnicity, gender, and business title (eg, escort, companion).
Business practices	Business practices refer to communications that detail the dollar amounts associated with the cost of sexual services, contact and booking processes, and related restrictions.

^aCommunication was defined as the process of sharing information and conveying meaning through a shared system of semiotic rules and symbols [35]. Hypertexts or the array of words, phrases, and images found within advertisements were the focus of data collection [32].

^bHIV: human immunodeficiency virus.