Delivery memos... one of a photographer's best friends. In a nutshell the DM serves as proof of custody for slides or print film. From an advertising company standpoint, whenever a photographer hands photographs over to me I have to sign a DM proving that I have taken custody of the material, how many I have taken custody of, a brief description of each image and in what condition they are in. While I have the photographer there, if possible, I put the slides on a light box and check for any damage that I don't want my company to be blamed for.
After everything checks out, I sign the DM and give a copy to the photographer. Now they are my responsibility. If I need to send one to a printer or someone else, we go through the whole process again with whomever I am turning them over to.
As a photographer, my delivery memo consists of my company information and info on who I am turning the images over to. The next section is about the images themselves, let's say slides. Each slide gets it's own description line that covers what is the subject of the image, the ID number, the condition of the slide and most importantly the value of the slide. This is not what I may be paid for the use of the slide, but the replacement value. Since this is an original work of art and as such not replaceable the value should be high. I have worked with local photographers that value each slide at $500 and national photographers that value theirs at over $10K each. Considering that when photographers hand over many slides of a subject, sometimes as many as 100 of them to fill a need for say, outdoor winter sports, the amount of money we are talking about is not insignificant. You can see why proof of how many images and in what condition the slides are in in pretty important.
After the project, when the photographer is getting their images back, I do the whole thing in reverse. The photographer and I go through the images again to verify that all slides are there and in good condition, we sign DM's showing that custody of the material goes back to the photographer and all is right with the world. I have every incoming and outgoing DM that I have ever done in my files.
As a side note, whenever I take custody of images from a photographer, the material immediately goes into a big fireproof gun safe. At any time I have around 1,000 images from photographers in there. When handing over images to someone, it is not a bad idea to ask how the material will be stored.
When I first started my company I had about 150 images from a photographer, the DM put the value per slide at $1500, yep $225,000 worth of images. One of my designers left the box of slides on her desk. That night the cleaning crew knocked the box off the desk and into the garbage can. When they were done they took out the trash like they were supposed to... with the slides to the dumpster. After we came in the next morning (TRASH DAY), we realized the slides were missing. We finally determined what had happened and we spent the better part of an hour going through the dumpster. Hence... the big safe!