Rs698

dbSNP says its multiallelic and on the minus strand. In 23andMe results T is reference and C is minor.

rs698 is also known as Ile350Phe, and is a SNP in the alcohol dehydrogenase 1C ADH1C gene. The rs698(A) allele is the more common, encoding the amino acid isoleucine (Ile); the quite rare rs698(T) allele encodes the variant phenylalanine (Phe).

On it's own, this SNP is said to explain 12.3% of the variability in the rate at which alcohol is metabolized, based on a study of 250 Spaniards.

More significantly (in a statistical sense), this study concluded that combinations of this SNP and others were shown to affect alcohol metabolism; most of these combinations are represented by the gs211 genoset.

Note that the effects of alcohol are higher in individuals who break down (basically, detoxify) ethanol more slowly.