I used these business card-CDs last year for a Flash-based sales presentation. I can't speak for the recording process, as we outsourced the production and labeling, but they played fine in most of the machines in the office (the exception was a couple of ancient DEC machines that were being kept around for testing purposes). They should work with any tray-loading drive that is not too old. I interpret the warning on the box to be referring to: caddy-style: The old-school 1x and 2x drives that required the disc to be loaded into a sealed plastic "caddy" and then inserted into the drive. front-loading: front slot loading drives, resembling a car CD player. i know Pioneer used to make these. I wouldn't risk attempting to play a mini-CD in one of these, as I'd be afraid it would never come out... -pete. > This weekend, when I was out looking for some CD-R discs....I > found something that made me curious. The store I was in had CD-R discs > that were in the shape of a business card. I thought these would be > great to send to potential clients - very memorable...so, I read the box > and it said that they couldn't be written with "caddy style or front > loading CD-RW drives". Now, I've used the mini-CD-R discs for awhile, > and found that they *do* make an impression on businesses when presented > with them....so, I'm thinking that these business card size ones would > make even more of an impression - BUT, I don't want to spend the money > if I'm not going to be able to write to them, or if my potential clients > won't be able to read them.