The process of writing more audio or
data than the official capacity limit on a
compact disc. Overburning a CD depends on the
type of media, the software and writer being used.
Also called oversizing.
CD-R Media Overburning According to the redbook standard (the standard at which all CD.s are based on) the leadout must be 90 seconds. Usually you can even write beyond these 90 seconds but then the data may be unreliable.
PC TechGuide - Overburning The Red Book standard for an audio CD specifies a capacity of at least 74 minutes plus a silent "lead-out" area of approximately 90 seconds, used to indicate the end of a disc.