LCN in DVB-SI

In DVB SI (ETSI EN 300 468),
it says the descriptor id in the range of 0x80 to 0xFE is user defined.

0x83, in the range, is used for LCN (logical channel number) descriptor.
Which make me confused that how could a used-defined id be adopted to use on the relatively important LCN? It should use a public one.

Then I found some discuss about this non-standard usage.
And found that it's defined in DVB Europe E-Book.


And here is a article about how those specifications used.