Yes, JPEG, TIFF and PNG files for example. But, if you modify any of
these with an application that doesn't support the extensions then
you will loose them.
Also, you are thinking _very_ narrowly now. There are thousands of
file formats. Implementing the support for meta-data/ streams/
attributes in the kernel will make it possible to use this
generically for all files.
I use this in Windows quite much. I put information description
fields for lots of different files. These descriptions are then
searchable etc. I could use the command prompt to copy the files and
the descriptions would still be there.
Secondly, do you expect file managers like Nautilus and Konqueror to
support every piece of file format on the planet so they could read
information directly from the documents?
~S