I also noted today that 'types' screw up negative AC effects.
Example:
AC:-3 armor;AC:-3 shield
these are ignored..
AC:-3
works fine...
So you can't use an effect to remove your shield for example... or to temporarily take off your armor & shield while using 'Wild Shape'.
You CAN add your armor & shield as effects and then remove them when using wild shape... I'm not sure this is great.. but it can be done.

