Final answer:
The WHMIS 1988 supplier label is recognizable by its distinctive hatched border, which encloses symbols signifying hazards. This is distinct from the NFPA system, which uses color-coded diamonds to indicate various hazards.
Step-by-step explanation:
The most obvious way to know you are looking at a WHMIS 1988 supplier label is by the hatched border that is typically utilized around the label. The Workplace Hazardous Materials Information System (WHMIS) is a Canadian system in place to provide key information about hazardous materials in the workplace. The WHMIS 1988 version, in particular, relied on distinctive symbols and labeling conventions that are not to be confused with the National Fire Protection Agency (NFPA) 704 Hazard Identification System's fire diamond. WHMIS labels are recognizable for their specific graphic symbols enclosed within distinctive hatched borders, signaling different types of hazards, and not the color coded diamonds such as red, blue, yellow, or white used in the NFPA system to denote fire hazards, health hazards, reactivity, and special hazards respectively. Note that the answer is not directly provided in the reference material but is general knowledge about the WHMIS 1988 system's labeling requirements.