“C170” is often used as a market label tied to a cationic grade family where the emulsion is intended for road surfacing and maintenance works that need controlled breaking and reliable adhesion. In practice, it is commonly positioned for surface dressing, patching mixes, and certain cold mix or maintenance applications, depending on local spec definitions. The correct approach is to treat C170 as a commercial designation and verify the governing standard reference, binder content, viscosity window, particle charge, sieve residue, storage stability, and residue performance before purchase, because naming conventions vary by region and supplier.