Which standard to annotate the pics ?

[yb98]

I'd like to add some information to my pics such as keywords, description, categories,etc. and I'm wondering which standard I should use ? is IPTC the standard which will be the most used in the futur or are there others ?
Also which best software to use to annotate and make search using such information ?
Finally is it possible to add such information to raw files or only jpeg ?

[Scottes]

EXIF might be better, but I'm not sure if it has all the fields available like IPTC. If you did use EXIF there are a lot more programs to read/write the info. (At least it seems that way to me.)

I would not touch the RAW file. Maybe that's just my paranoia. But it seems like it would be like scratching your copyright on a slide...