From UO Evolution
List of Skills
Each page details what a given skill does, how it is used, and the best methods to train it.
There are powerskulls in game that will allow you to pick which powerscroll you would like to have from a menu. The skulls can be found as bod rewards, on boss monsters, arty credits, events or by donation
Powerscrolls allow you increase a skill's cap over 100. Scrolls are found in 105, 110, 115, and 120 denominations for each skill. Powerscrolls drop from the Monster Invasion System and Champion Spawns located throughout the Felucca facet. You must defeat the boss and do damage to be eligable to get a scroll drop.
There are also powerscrolls that are earned from bods and from secret vendor stones
The stat cap is set to 300, but it can be increased up to 350 with stat scrolls. The stat scrolls range from +5 up to +50. These scrolls are not stackable, so you must find a +50 to get that increase. The Harrower drops these scrolls in game.