[MBV53]

It is not mandatory to alert popular conventional Bids, In your opinion alert of 4th suit is a must? in a bidding sequence NS reaches 3NT contract. south applies 2C as 4th suit, North player withJ42 clubs bids 3NT. East holds Q2 of clubs, leads a spade, Declarer makes +2, where as west holding of clubs AK10 85, club lead sets 3nt-1. your views are sought! Remember there are no automatic Rectifications for not alerting!
MBVSubrahmanyam.

[spotlight7]

Hi:

When south bid 4th suit forcing 2C and west held AK10xx a leading directing double is the call.

If they bid 3NT after the double, east with Qx of clubs leads the Q and you take your tricks.

Regards,
Robert

[barmar]

Alerting rules are set by the tourney host. In an ACBL game, 4th Suit Forcing is alertable.

[helene_t]

Online alerting procedures are extremely simple. Explain everything spontaneously if you have a partnership understanding about it beyond what opps already know.

So it is often appropriate to alert fsf. I would not alert it, though, if
- it is a situation in which it may or may not apply, and I don't know how partner will take it
- opps are smart enough to understand that it is obviously fsf

For example, if playing if the main room with a pickup partner, opps know we are pickpup partners, we agreed to play "vanilla 2/1" which is a concept that opps know just as well as p and I do, I would not alert anything.