You can add to a maximum 10 Skill Points.
HP Recovery level 3
Adds a HP Recovery that works at any given time every 8 seconds for a very small amount HP. Unlike normal HP Recovery, you see a green number like if you had caught an item. The timer is paused while sitting.
The regen value is a percentage of your base regen value (ignoring Increase HP Recovery). The percentage goes from 7% at level 1 to 25% at level 10, adding 2% per level.
Compare to Increase HP Recovery, which adds 20% per level, and works even while sitting. (Is there something more to this skill?)