From my notes, here’s a paradox he offered at a Copenhagen self-reference conference in 2002:
Have you heard of the LAA computing company? Do you know what LAA stands for? It stands for ‘lacking an acronym.’
Actually, the above acronym is not paradoxical; it is simply false. I thought of the following variant which is paradoxical — it is the LACA company. Here LACA stands for ‘lacking a correct acronym.’ Assuming that the company has no other acronym, that acronym is easily seen to be true if and only if it is false.