Compound markers (#) should only be used if two or more transparent, or in simplified terms 'meaningful', units can be separated. A meaningful unit in that sense is a content word that keeps its meaning even though a second unit is added.
Example: Fernsehturm f'E6nze:#t''U6m dunkelblau d'UNk@l#bl"aU staubsaugen St'aUp#z"aUg@n
Not marked, however, is:
Example: Bahnhof b'a:nh''o:f
This is due to the fact that a 'Fernsehturm' is still a 'Turm', while a 'Bahnhof' is not a 'Hof' anymore.
Parallel to that not marked are constructions with prefixes and suffixes, as in these cases only one 'meaningful' unit is involved.
Example: vorlesen f'o:6l''e:z@n Sicherheit z'IC6haIt
Units representing truncated words or slips of the tongue do not receive
any compound markers.