clientErrors isn't documented anywhere

[cideM]

The ApolloError type has a field called clientErrors, which you can find here

This field seems to not be documented anywhere. For example, searching for clientErrors on this page gives me zero results. It appears to have been added in this commit: 09ac78aadb928727346b73d5a5bd196153fb9764.

Considering the complexity of error handling it would be good if it was clearly stated what the purpose of this field is so it's easy to decide how to handle it. Should I refetch? Should I show it to the user? What are typical conditions when it comes up?