pf2e.fyi
From Pathfinder Impossible Magic, which isn't enabled.

Living Lexicon

FEAT 18

Your knowledge of runes knows no bounds. You add an additional rune to your runic repertoire of any level. Additionally, each day during your daily preparations, you can swap any one rune in your runic repertoire with another rune of the same level.

Pathfinder Impossible MagicORC