Found in Healthy Savings IVC booklet:

Buy any 2 participating Vicks items, get $5 RR. Items include:
NyQuil Less Drowsy liquid, 10 oz
DayQuil Mucus Control liquid, 10 oz
VapoSyrup liquid, 10 oz
NyQuil/DayQuil 20 ct LiquiCaps or 10 oz liquid
NyQuil + Vitamin C/DayQuil + Vitamin C, 20 ct caplets
Vicks 44 liquid, 6 oz

offer good 9/27-12/26/09

This is a P&G promotion, so keep in mind that the P&G RRs state that they are not to be used on P&G products. Walgreens Register Reward: P&G register rewards announcement