Use Arg request, response
response~content_type = "text/plain"

-- [] now always reaches the environment pool, even for a name that
-- matches a method: ["content_type"] is the raw CGI variable, not the
-- request method.
Say "bracket_method_name=["request["content_type"]"]"

-- A standard CGI variable through [] (was already pool, still pool).
Say "bracket_server=["request["server_name"]"]"

-- An operator-set variable with NO leading underscore, reached both
-- ways. Under the Action sub-request it arrives REDIRECT_-prefixed and
-- the general pool fallback recovers it.
Say "plain_msg=["request~myplain"]"
Say "plain_bracket=["request["myplain"]"]"

-- An operator-set variable WITH a leading underscore still resolves
-- (no longer a special branch -- just another pool name via the same
-- REDIRECT_ fallback).
Say "under_msg=["request~_myvar"]"
Say "under_bracket=["request["_myvar"]"]"
