If Declarer opens One ♣️ or One ♦️ or One ♥️ and partner responds at the same level (excluding One No Trump), is it Alertable if Opener can Pass the Response?
"4 H2 Because they have a potentially unexpected meaning, players must alert:......
(d)A non-forcing new suit response,to a non-forcing suit opening at any level, below game, unless responder has previously passed, bids over a natural NT overcall, or makes a double jump...."
So the answer to your question is that in England it is alertable unless the responder is a passed hand. Other jurisdictions may vary.
Comments
In England the Blue Book states:
"4 H2 Because they have a potentially unexpected meaning, players must alert:......
(d)A non-forcing new suit response,to a non-forcing suit opening at any level, below game, unless responder has previously passed, bids over a natural NT overcall, or makes a double jump...."
So the answer to your question is that in England it is alertable unless the responder is a passed hand. Other jurisdictions may vary.