The item description is:
"This slip allows the customer to store
one piece of Relic +2 armor with a
porter moogle."

However, this item does not do this. And there is NO in-game indication as to what this item does.

In fact, this item only allows FULLY AUGMENTED Relic +2 armor to be stored. The only way a player can find this out? Wikis. The moogle's list of storable items and the slip description do not give ANY indication that this is the case.

The description really should read as follows:
"This slip allows the customer to store
one piece of fully augmented Relic +2
armor with a porter moogle."