Ceremonial Codex

Two Questions about the Ceremonial Codex.

Previously, it was stated that the Ceremonial Codex, is Tradition-specific.

So if a Ceremonialist finds a Codex containing ceremonies he doesn't know (not in his own repertoire), and wants to perform them as Unknown Ceremonies, does it make any difference if it matches one of his own traditions or not?

In the Ashley J. Williams Memorial rule, there's an extra -4 for attempting a ceremony as a non-ceremonialist (definitely not your tradition) without any implements at all. It then goes on to state that any Ceremonialist proficiency prevents incurring that, without mentioning if the traditions have to match.

My second question, is when is your Codex needed?

Performing Ceremonies on HFH page 107 says performing a ceremony is like cooking a recipe, without stating you need the recipe book on hand.

If you do need the codex to perform a ceremony, learning it merely prevents the -4 penalty and reduces disasters on failure.

If you can perform the ceremony from memory, when does your codex get used?

Do you need it to refresh your repertoire after a stigma purification? (that would parallel the Arcane repertoire refresh each day)

So if a Ceremonialist finds a Codex containing ceremonies he doesn't know (not in his own repertoire), and wants to perform them as Unknown Ceremonies, does it make any difference if it matches one of his own traditions or not?

No, it doesn't.

If you can perform the ceremony from memory, when does your codex get used? Do you need it to refresh your repertoire after a stigma purification? (that would parallel the Arcane repertoire refresh each day)

I didnt' make this explicitly clear, but the codex works precisely as an arcane spellbook does with regard to access. You need to have access to it every day, and without access to it, ceremonies fade from your repertoire. But you don't need to literally have it open and in hand while performing the ceremony if it's in your repertoire.