(i)

as between supplies that are identical from the point of view of the consumer; or

(ii)

as between similar supplies that meet the same needs of the consumer; is that of itself sufficient to establish an infringement of the principle of fiscal neutrality or is it relevant to consider (and, if so, how)

(a)

as a matter of national law, the comparator supplies were subject to VAT but

(b)

the taxing authority of the Member State had a practice of treating comparator supplies as exempt from VAT?

(a)

is it necessary that the taxing authority has made a clear and unambiguous statement that comparator supplies would be treated as exempt from VAT;

(b)

is it relevant that at the time the taxing authority made any statement it had an incomplete or incorrect understanding of facts relevant to the correct VAT treatment of the comparator supplies; and

(c)

is it relevant that VAT was not accounted for by the taxpayer, or sought by the taxing authority, in respect of the comparator supplies, but that the taxing authority has subsequently sought to recover that VAT, subject to the normal domestic limitation periods?

(i)

the tax authorities subsequently change their practice;

(ii)

a national court subsequently holds that the amended practice reflects the correct meaning of domestic legislation;

(iii)

the Member State is precluded by domestic and/or European law principles, including legitimate expectation, estoppel, legal certainty and non-retroactivity, and/or by limitation periods from collecting the VAT on the supplies previously regarded as exempt?