In Bridge4Free there is no Self Alerting, you have to alert your partners bid
Below is a guide line of what is alertable
- Alert a 1C opening bid if you are playing a Strong Club system, or if partner could have fewer than 3 clubs, but don’t alert a 1C or 1D opening that shows at least three cards in the opened suit
- Alert transfer bids. Alert all completions if you are allowed to break the transfer since even a simple completion carries a message
- Alert Stayman. You must also alert a 2D response though this is not a serious offence if you are playing ordinary Stayman. (Our TD is very unlikely to adjust a score for you if your opponents don’t alert Stayman and you don’t ask, even though it is alertable).
- Alert all Game Force bids (eg 2C) and conventional responses (eg denial, relay, step). (Again, our TD is very unlikely to adjust if a 2C opener or 2D response is not alerted and you don’t ask, even though these are alertable.)
- Alert any forcing responses to opening bids or overcalls with a special meaning eg Ogust, splinters, cue bids, Jacoby 2NT, Inverted Minor Responses and alert non forcing change of suit responses to an opening suit bid if an unpassed hand.
- Alert Benji 2C and 2D bids and conventional responses
- Alert any two- or three-suited calls (eg Lucas/Tartan 2s, Multi 2D, Michaels, UNT, CRO, some 1NT defences).
Don’t alert doubles unless they have very unusual meanings. Very unusual doubles include (and are not limited to):
- Doubles of opponents’ opening 1NT that are not for penalties
- Doubles of RHO’s natural suit overcall of partner’s suit opening that are for penalties (because most players use negative doubles here).
- Doubles that ask for a different lead than in the suit you have doubled (eg Lightner doubles, Non-lead doubles)
Don't alert any 2-level openings if they show one natural long suit, whatever agreed strength, but do alert if the bid has any other meaning eg a 2 suited hand
Don't alert NT openings if they are natural and balanced, but do alert if you have an agreement that you may hold a singleton (in which case, it isn’t balanced). Do alert a 2NT opening that shows the minors
Don't alert (nowadays the software won’t let you alert) bids above 3NT eg Blackwood, rkcb, Gerber - except if a conventional bid on the first round of the auction.
FINAL WORD OF ADVICE
Alerts are there to help and inform. They are not there so you can score bridge-lawyering points off opponents who don't alert "obvious" alertable calls like some above
The general rule is "if not sure then alert"
Then, if you are declarer or dummy, explain anything that you think opponents may not know before the opening lead. But if you are defending, don't explain (as it gives Unauthorised Information (UI)) until end of play.