Rules for creating war cards

[Naughtical]

Is there an official rule or rules for creating war cards somewhere? I recently acquired a few Birthright books, and I noticed that the various war cards don't match up exactly. Also, is there a list of standard special abilities, such as pikes not being able to be charged?

[AndrewTall]

I don't think so, some of the members who have posted new warcards might have used their own guidelines and still be around to share them.