Kelly Rutherford -- I Need A Script ... To Talk To My Ex

Kelly Rutherford's custody battle with her ex-husband is so hateful … they're now under a court order to speak politely to each other, and get this -- in certain situations they're legally required to follow a SCRIPT!

The custody orders -- obtained by TMZ -- spell out precisely what Rutherford and her ex, Daniel Giersch, can and can't say … and how to behave around their 2 young children.

The docs order them to "exchange polite and friendly greetings." And Giersch, who's German, has to speak in English whenever they meet for the hand off. -- so he can't trash her in a foreign language without her knowledge.

If a kid doesn't want to leave one parent ... there's a drill for that, too ... the adults must follow a script that's actually included in the court order:

"Have a great time with [other parent]. I'll talk to you tomorrow," and will say to the other parent, "[Name], please come and help me."