Adding a secondary workplace for an E-2 visa

I'm looking to get a secondary job added to my ARC. I know I need a letter of permission from my employer, but what does this letter have to say? Is there an official way of doing it or can my employer just pretty much write the equivalent of "As XXX's visa sponsor, I give permission to XXX to work at another institute."?

Re: Adding a secondary workplace for an E-2 visa

It's been a few years since I've done this, but when I added additional work, I needed a contract from the additional job and a letter of permission from my visa sponsor.  I don't think there was an official form that my job had to fill out--basically just a letter stating that I had permission to do the additional job.

Note that you DO need a contract from the additional workplace.  The extra job will be added on the back of your ARC.  You don't simply get blanket permission to work at other places.