CodespeakSource Black Markets pg. 24, Second Darkness Player's Guide pg. 26 (Amazon)
School transmutation; Level arcanist 2, bard 2, inquisitor 2, shaman 2, skald 2, sorcerer/wizard 2
CastingCasting Time 1 standard action
Components V, M (a knotted serpent’s tongue)
EffectRange close (25 ft. + 5 ft./2 levels)
Target you and one willing creature per 2 caster levels, no two of which can be more than 30 ft. apart
Duration 10 minutes/level
Saving Throw no; Spell Resistance no
DescriptionAll recipients gain the ability to speak, write, and understand a unique language. This language sounds like random syllables and looks like written gibberish to anyone not under the spell, but the targets understand each other perfectly. Once the spell expires, any codespeak writing is unintelligible even to the targets. Each spellcaster creates a unique but constant secret language, and later castings of codespeak by the same caster allow new targets to understand messages left behind by others affected by the same spellcaster.
Comprehend languages does not enable a caster to understand the language of another’s codespeak spell, but it does reveal that the targets are speaking a magical language. Tongues and similarly powerful spells translate codespeak normally. Add your caster level to the DCs of Linguistics checks when attempting to decipher messages written in codespeak.