diff --git a/src/net/net.go b/src/net/net.go
index f8b5834acb..82dc222de1 100644
--- a/src/net/net.go
+++ b/src/net/net.go
@@ -68,6 +68,11 @@ GODEBUG environment variable (see package runtime) to go or cgo, as in:
 
 The decision can also be forced while building the Go source tree
 by setting the netgo or netcgo build tag.
+The netgo build tag disables entirely the use of the native (CGO) resolver,
+meaning the Go resolver is the only one that can be used.
+With the netcgo build tag the native and the pure Go resolver are compiled into the binary,
+but the native (CGO) resolver is preferred over the Go resolver.
+With netcgo, the Go resolver can still be forced at runtime with GODEBUG=netdns=go.
 
 A numeric netdns setting, as in GODEBUG=netdns=1, causes the resolver
 to print debugging information about its decisions.