For Staple.com, the billing section, this is for the exp date:

title="overall type: UNKNOWN_TYPE
server type: CREDIT_CARD_EXP_2_DIGIT_YEAR
heuristic type: CREDIT_CARD_EXP_DATE_4_DIGIT_YEAR
label: Expiration Date*
parseable name: expDate
section: credit-card-cc
field signature: 3378969197
form signature: 5974473966832628557"

The server prediction used to be username, but we did an overwrite.