Regarding the "RS380" bit - here's a bit:
...in other words - it could be somewhat "standard" - or no standard at all, and just what the company decided to label it with. If you really start to dig into it (google "rc brushed motor sizing" for instance), you'll basically find the same thing - that these numbers used to mean something, but over time manufacturers have either exaggerated claims, marked the motors in such a way for marketing purposes, or the numbers don't mean anything.