what format mp3 cd`s

[MoneyMike]

• Make sure the MP3/WMA files are recorded on a
CD-R disc.
• Do not mix standard audio and MP3/WMA files on
one disc.
• Make sure each MP3/WMA file has a .m3u or
.wma extension, other file extensions might not work.

Just a few questions.

1. So you can mix MP3 & WMA files, as long as there aren't standard files?

2. Does this mean no .mp3 extensions?

3. Is it possible to covert files to the correct ones? I think I did this once before, but that was very long ago.

EDIT: I want to make sure, as I was gonna do a couple. One for me, and one for my dad. My dad thought that there was a special disc for this type of thing.