There are a number of caps in UO related to properties and abilities.
For stats the max unehanced value for a stat is 125. The max enhanced value is 150.
For Regeneration there is 18 Cap on items, and No Cap on Magical effects.
Resilience is a magical effect and so is not subject to that 18 Cap. (Resilience should stack with HPR on suit )
For Damage Increase, and Damage Modifier properties, the item cap, and the magical effect cap is the same, so if you cap out items, magical effects don't help, or if you cap out magical effects items don't help.
(Same for HCI and DCI, though direct amount reduction effects maybe negated by overcapping. Pre change HLD used to be a direct -25 to DCI)
For preservance there's also the Damage reduction which takes place after resists are taken into effect, and applies to all damage, including direct damage.