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After plant/function and location follows what was previously (IEC750) referred to as the component level, in this case –F1. In IEC1346, minus instead is interpreted as "product". However, in many cases, this is the same thing. This means, that IEC750 in many ways can be regarded as a sub-set of IEC1346.

 

The minus sign is followed by the so-called "component type letter code", in this case the letter F. The component type letter codes that can be used are defined by the IEC1346 standard (or the older IEC750). In our example the letter F means "protective devices". (And in this case the counting number following it refers to protective device, or fuse, number 1.) Other typical letter codes are M for motors and S for switches.

 

As already mentioned, IEC750 specified that a minus sign should be used as prefix for the component type letter code, while IEC1346 specifies that minus should define "product". The result in many cases, is the same.