Due to a problem with spam, I’ve been tasked with writing a PHP front-end for registrations to our jabber service. Unfortunately the documentation  on what is acceptable input is lacking. I did manage to find out the field sizes by looking at the database documentation, but would like to be sure that what I pass on to the User Service plugin is valid and wont cause problems.
I don’t know Java, but I did try to look at the User Service plugin’s source. Unfortunately I have no idea what a jar.pack is (neither jar, nor pack200 worked on it and file just identified it as data), Google was no help either.
So my questions are:
What is considered valid characters for each parameter?
Will urlencode’d or rawurlencode’d data be accepted?