Image Comment feature on the Canon a540?

[DouglasUrner]

Nikon has a nice feature that they call "Image Comment" that enables you to add some custom text to the metadata the camera saves with each image. I think the feature was also included in some of the Nikon P&S cameras. I'm looking to buy a bunch of P&S cameras for a high school photography program and would like to use this feature to "tag" the cameras so that I could tell which camera was used to produce a particular image. I'm thinking it would be helpful for troubleshooting -- and that it might even reveal the existence of a "missing" camera (obviously I'm not counting on this, but I wouldn't complain if it happened :-).

Does anybody know if a feature like this is supported on the Canon 'a' series P&S cameras -- particularly the a540?

Thanks, Doug