What the max disc label when recording CDs/DVDs?

When doing backups, I get confused about the max character size of the disk label when recording CDs/DVDs. It's fixed size or follow some standard?

From serverfault Click Ok

• The max character size does follow a standard. This webpage gives a good summary about the differences in the formats:

  http://msdn.microsoft.com/en-us/library/aa364836(VS.85,loband).aspx

  From Joseph