Event Forwarding: documentation for 'arc' and 'utils' variables

[BarryTL]

When I start to create a new Data Element in an Event Forwarding property with "Data Element Type" set to "Custom Code", the default code includes a notification that the 'arc' and 'utils' variables are available.  Where is the documentation that explains these variables?

There are scattered mentions of both 'arc' and 'utils' in the Adobe documentation, but nothing that actually documents the available methods or use cases.

[VKannan17]

I believe this will help https://experienceleague.adobe.com/en/docs/experience-platform/tags/extension-dev/edge/context

[BarryTL]

Thanks, @VKannan17 - that is one of the few places I could find that mention the variables.  Do you think that's the extent of the documentation around 'arc' and 'utils'?  I had actually read that document to be aimed at developers of Extensions for use in Event Forwarding.