It is used as a for construction materials, such as specific types of cut-off wheels (e.g., 14" 7-7-0 PC/S
It could be a sequence of characters or a version number found in technical documentation or historical archives. Observational results of x-ray astronomy - SciSpace 7-7-0-pc
The phrase is ambiguous and could refer to a few different things depending on the context: It is used as a for construction materials,
