[awm]

Australia is known as having some of the most permissive rules regarding conventions of any country in the world. In contrast, the United States is known for having some of the least permissive rules. Nonetheless, I was looking at the Australian regulations (available at abf.com.au) and noticed this:

Brown Sticker Conventions and Treatments...

b: An overcall of a natural opening bid of one of a suit that does not promise at least four cards in a known suit.

Exceptions:
i. A natural overcall in notrumps.
ii. Any cue bid that shows a strong hand.
iii. Any cue bid in an opponents known suit that asks partner to bid 3NT with a stopper in that suit.

Of course, brown sticker treatments are not disallowed as such, but they do place a burden on the side using them, including:

(1) They can't be used against novice pairs, or pairs where one person is a novice. (protected pairs)
(2) Players using brown sticker methods need to pre-alert/disclose this fact. (it's marked with a colored sticker on their CC)
(3) Written defenses/notes are allowed at the table when defending against brown sticker methods.

The curious thing is that 1NT showing a weak takeout of opener's natural suit bid, a popular part of overcall structure in the USA which is General Chart and does not require a pre-alert or suggested defense, would seem to be brown sticker by this set of regulations.

[paulg]

Stones ... glasshouses

[skjaeran]

This BSC definition is in fact the same we use in Norway, and it's a blueprint of the WBF System Policy BSC definition.

[helene_t]

The Australian rules sounds reasonable.

Maybe this 1NT as a weak t/o is not particularely difficult to defend (I suppose one could play the same defense as against a natural 1NT overcall) but if one wants to BSC-label any overcalls at all, simple criteria like the Australian ones make sense, I think.