5% is the maximum voltage (Tol) that can be supplied.Zener single diode is important to note that during operation, the maximum voltage - Zener (Nom) is reduced to 12.8V.Zener single diode reaches 0.64mV/°C when the voltage (Temp Coeff) reaches maximum.
1N4897 Features
1N4897 Applications
There are a lot of Microsemi Corporation 1N4897 applications of zener single diodes.