This is some extra information that I manage to gather from Taiwan SRO guide. Its on the premium guide, so I would assume that the information is correct.
Each Weapon/Armor/Protector/Garment/Accessories will have a Phy. and a Mag. Reinforce Value. According to the guide, Phy. and Mag reinforcements are just a set of useless numbers if Elixirs are not used on it.
Lets look at this picture (sorry that its a Taiwan Version)
http://img220.imageshack.us/my.php?image=110ru8.jpg
Reinforces of the weapon are as follows:
Physical Reinforce of the weapon is 53.5% ~ 63.5%
Magical Reinforce of the weapon is 94.0% ~ 115.0%
It basically means that with every Elixir used on the weapon that is successful, it will add Physical Damage of 5 ~ 6 and Magical Damage of 9 ~ 11 on it.
The picture shows a b4 and after the Weapon (+1) itself. At (+1) its Physical Damage was increased by 5 and Magical Damage by 10.
Hope this helps. Correct me if I am wrong. Cheers.