Let us take a universal relay with the model number as follows: T60-G03-ACH-F8H-H6M-MXX-PXX-UXX-WXX. In order to understand what each of the alpha numeric options mean and which modules are included in this particular universal relay, one must consider table 2-4 in the product manual which breaks down the T60 order codes of this GE Multilin universal relay. The skeleton order code is T60-***-***-F**-H**-M**-P**-U**-W/X**. Each * indicates a point within the model number that is variable. This allows the end user to select a specific hardware module such as a CPU or in this case a digital I/O module into the universal relay in certain position. In some cases, the * also indicates if a software option is included or something that is not necessarily tangible. If we look at the digital input/output section in the order code breakdown then we notice that a potential digital I/O module could specify a two digit order option in the missing (asterisk) locations following the H, M, P, U, or W spaces. The digital I/O modules have the two digit code that begins with a 4 or a 6. If we look back at the part number used as an example, one can notice a 6M following the H location. Therefore a UR-6M Digital I/O module is incorporated into the universal T60 relay at that position. Whenever XX is found in the model number this means that there is no module at that location.