So, I just got done speaking with an associate at Always and here's the deal.
I asked if the 20 count pantiliners was considered travel/trial size and this is what I was told. "It is entirely up to the store as to whether or not they want to allow the coupon to be used on that product in particular. We do not see any problem with the coupon being used on that product, but if it goes against a store policy, they have every right to say they will not accept that coupon for that product. If you are turned away at one store, maybe just try a different store and see if they accept it."
In other, less confusing words, you can use this coupon on this product but it's up to the store you use it as to whether they will or won't accept it. So go ahead and use it and if you run into issues, try a different store. I know they are exactly $1 at Dollar General so you won't have any upset there.