38.3 Electric energy storage systems shall also be marked with the date of manufacture, which may be in the form of a code that does not repeat within 20 years.38.4 An electric energy storage system intended for use with specific chargers shall be marked with the following or equivalent: ″Use Only ( ) Charger″.38.5 Electric energy storage system evaluated for protection against ingress of moisture per 5.3.5, shall be provided with the appropriate IP Code rating.38.6 Systems shall be marked with a cautionary marking indicating to read all instructions before installation, operation and maintenance of the system. This marking may be in the form of the symbol(s) for example: the Standard for Graphical Symbols for Use on Equipment – Index and Synopsis, ISO 7000, ″caution″ Symbol No. 434 (exclamation point inside triangle) followed by the ″read instruction manual″ Symbol No. 790 (open book). If using symbols, their meaning shall be explained in the instruction manual