2002 century dash light question

On my 02 Century a dash light comes on that says trac off whenever the transmission is dropped into 1st or 2nd, or when the emergency brake is applied.

I have the originial owners manual and a Haynes service manual and they make no mention of this light at all.

I'm sure it's nothing to worry about. Was just curious as to what its indicating.

jhn9840
John