As far as we are concerned, there is no question and it turns out that we are not alone in condemning the use of  ‘the bastard conjunction and/or’.
As early as 1932 the American Bar Association Journal described it as an ‘accuracy-destroying symbol’ and ‘a device for the encouragement of mental laziness’. This sparked a debate between the ‘Andorians’ and the ‘anti-Andorians’. We are resolute anti-Andorians, because we feel that even though it may save a few words, it is (at best) difficult to understand and (at worst) inherently ambiguous.

‘And/or’ means ‘the one or the other or both’. In cases where that distinction is necessary, it is good practice to choose the unambiguous ‘the one or the other or both’. If you  find on the website of a hotel the information that “every room has a bath or a shower or both” instead of “every room has a bath and/or a shower”, you as customer will clearly know what to expect.

Much to our delight, we stumbled across some authority for our convictions in Berman v Teiman 1975 (1) SA 756 (W) 757D-G. That case led us to the decision in  in Conitto v Fuerst Bros. & Co. Ltd., 1944 A. C. 75 which gave us ‘the bastard conjunction and/or’. It also pointed us to the case of In Re Lewis, Goronwy v Richards, (1942) 2 All E. R. 364 (Ch) in which judge said that: ‘It is an unfortunate expression which I have not met before  and which, I hope, I may never meet again.’ And finally in Fadden v Deputy Federal Commissioner of  Taxation, (1943) 68 C. L. R. 76 it was described as ‘an elliptical and embarrassing expression which endangers accuracy for the sake of brevity’.

Our favourite however, came from our own shores when Judge van de Heever (in Ex parte McDuling, 1944 O. P. D. 187) pointed out that (and I translate): ‘You might as well say trousers is and/or are.’

Wondering if your consumer contract is in plain language? Turns out it can be sunk by two little conjunctions.