No one seems to recall it ever being used, however the old agreement remains in force.
The agreement remained in force as usual after 20 December 1999.
There remains no formal agreement to end the eight years of civil war that has cost at least 200,000 lives.
Article 16 stipulated that the agreement shall remain in force for 25 years.
"An agreement remains out of the parties' reach at this time," the three mediators said in a statement.
Ministers here said their willingness to continue talks suggested an agreement remained within reach.
The temporary agreement will remain in force until the end of July 2007.
The agreement will remain in place until one of the parties pulls out.
That is a point on which a final agreement remains to be negotiated on 15 March.
But it was written, and the agreement remained in place.