The Catalogues of Enlightenment (Planar Handbook, p. 166) is a touchstone site whose base ability is:
Base Ability: Choose a cleric domain; you gain the granted power of that domain.
Therefore, a character with the feat Planar Touchstone (Planar Handbook, p. 41) or the feat Touchstone (from Sandstorm), may forge a link with the Catalogues of Enlightenment and choose a cleric domain, gaining its granted power.
There are many cleric domains, though, and therefore a character may wish to switch to another domain.
I have not found any explanation of:
- whether switching the domain is allowed at all,
- whether switching entails attuning another touchstone site and then re-attuning the Catalogues of Enlightenment,
- or whether switching is as simple as a Free Action1.
Is there any rule or guideline for this?
1 Which, given that some granted powers are reactive in nature, such as the Pride domain's ability to reroll 1s on saves, would seem a tad too powerful.