A presentation by the President of doeLEGAL, Tom Russo, addressed how to design what he calls litigation spend architecture. On a slide having to do with how to start a matter you have assigned to outside counsel, Russo recommends, “Within five days – outside firm must file [an] Assignment Acknowledgement form.”
I did not hear Russo speak so I do not know whether he embellished or qualified this bullet point, but I have not heard of a requirement by legal departments that outside counsel formally acknowledge that they have been retained. These days, an e-mail should be quite sufficient and that a form does no more than create make-work on both sides.
If you are interested in the full presentation, please write Scott Miller of doeLEGAL.