Clarify Handling of IRDI pathes

[BirgitBoss]

Is your feature request related to a problem? Please describe.
Clarify if it is
(GlobalReference)0173-1#02-BAA120#008 (FragmentReference)0173-1#02-BAA144#008
or
(GlobalReference)0173-1#02-BAA120#008/0173-1#02-BAA144#008

Describe the solution you'd like
References keys were introduced to be able to build semantic ID pathes. So examples should be added that (GlobalReference)0173-1#02-BAA120#008 (FragmentReference)0173-1#02-BAA144#008 is the preferred way to do it.

Still clarification for blocks, counters etc. needed.