Agnostic Divine Casters

[Kazaan]

Divine casters have the option to either worship a pre-established deity and be subject to their domains, tenants, and preferred weapon or be deity agnostic and hold to the domains directly and establish their own personal tenants. But how does preferred weapon fit in for an agnostic divine class? Do you forfeit that benefit or do you select a preferred weapon when you roll the character? Any official rules and/or unofficial guidelines on the matter?

[Joana]

Jason Bulmahn says clerics without a deity don't get a favored weapon here.

[Beckett]

It's up to your DM. Officially, in PF all Clerics require a single deity, so that isn't an option. If it is not PFS and the DM is willing to work with you (honesly the vast majority of Clerics are already prof in their deity's favored weapon), it shouldn't be that difficult and not unbalanced to create a faith, including Favored Weapon and Domains. Other Divine casters really do not get Favored Weapon anyway, so it is just Clerics, for the most part.

Another good rule of thumb is to go off of alignment.

Good - Longsword
Evil - Heavy Fail
Chaos - maybe Rapier
Law - Warhammer

or prevailent concept such as. . .

Death - Scythe
Healing/Peace - Improved Unarmed Strike
Battle/War - Long or Great Sword
etc. . .