Question: h$... convention in jsbits?

While looking at the jsbits of various libraries (e.g. base) it is very common to find symbols prefixed with the h$ prefix. My mental model has always been that this is simply to avoid namespace pollution but this always seemed a bit odd given that Javascript has proper namespaces in the form of objects.

So, I ask: Is there more to this convention than there appears? Even better, is there a Note that could be pointed to which documents it? Do we lint that base's jsbits conforms to this convention?