. 2017 Feb 17;5(1):e2. doi: 10.2196/medinform.5054

Table 2.

Personally identifiable information (PII) combination patterns for hash cod.

Hash code	Combinations patterns
1	YOB + DOB + SEX + GIID^a
2	FN + MN + LN + COB + DOB + MOB
3	FN + YOB + MFN^a+ MLN^a+ FFN^a+ FLN^a
4	FN + LN + COB + SEX + MDOB^a+ MMOB^a+ FDOB^a+ FMOB^a
5	FN + MN + MOB + MFN^a+ FFN^a+ MLN^a

^aThe field that is optional.