When optimizing images for the web pages we found that it is very helpful to use descriptive file names that are understood by humans as well as search engines.

File names are used such as: 23.jpg or 100001523.gif. Especially CMS have the bad behavior to assign long numbers as file names to the images. This is a very technical solution and for the convenience of the programmers but very bad for the ranking.

Some "open source CMS" seem to be advanced in this regard and consider search engine marketing more and more. It is up then to the programmers to assign names. A name like visualorange_468x60.jpg for a banner, located in a banner folder, tells us about the size and the company name that is represented by the banner. There is no need to view it to check the size nor to which company it belongs. So it would make the life easier for programmers too, but it is still ignored heavily.