In the docs here:
https://golang.org/cmd/go/#hdr-Vendor_Directories

There is a single section that mentions how the behavior of go get changes when the GO15VENDOREXPERIMENT env var is enabled:

When the vendor experiment is enabled, 'go get' 
checks out submodules when checking out or 
updating a git repository (see 'go help get').

A source of confusion and many questions (twitter, slack) results from the assumption that running go get with the flag enabled will place downloaded packages into a vendor directory, which is not the case. A sentence or two added to the documentation would help:

When the vendor experiment is enabled, 'go get' 
checks out submodules when checking out or 
updating a git repository (see 'go help get'). 
The storage location of downloaded packages 
does not change with the experiment enabled; 
'go get' will not place retrieved packages into a
'vendor' directory. 

Is it possible to update the documentation prior to the next release?