The VideoLAN Forums

I wish to create a playlist in m3u format in a text editor. However the syntax is unclear. Here is a simple playlist created by VLC:
#EXTM3U
#EXTINF:137,20th Century Fox - The Simpsons Movie - Trailer
/Users/nealnt/Desktop/Quicktime project/simpsons.mp4
#EXTINF:89,The Bourne Ultimatum - Trailer.m4v
/Users/nealnt/Desktop/Quicktime project/The Bourne Ultimatum - Trailer.m4v

So how was the number 137 and 89 come from? Can I assign my own numbers? Where 20th Century Fox- text come from? It is not in the file name.Can I drop it or use any label I want?

The file paths make sense.

Is there a web site that defines all this?

Thanks