I am currently reading up about Genotype Arrays and the different nomenclatures that are used to report genotypes. In that context, it is important if the SNP is ambiguous or not (https://emea.support.illumina.com/bulletins/2016/06/simple-guidelines-for-identifying-topbottom-topbot-strand-and-ab-allele.html).
However, I could not find anywhere why a A/T or C/G SNP is considered ambiguous. I did not quite get the explanation here
I would be very grateful if somebody could explain to me why a A/T or C/G SNP is considered ambiguous.