Final answer:
Regulatory requirements typically mandate that a pharmacy's operating hours be posted on an exterior sign when they differ from the general merchandising establishment's hours, ensuring clear communication for customers regarding healthcare services.
Step-by-step explanation:
When the pharmacy is not open during all the hours maintained by the general merchandising establishment, an exterior sign shall typically indicate the pharmacy's operating hours to ensure compliance with regulatory requirements and to provide clear communication to customers. This is often a legal requirement and carries implications for consumer health and safety, as it ensures customers are aware of when they can access pharmaceutical services. This practice is part of effective business operations and customer service, and may be mandated by board of pharmacy regulations or other relevant laws.