ICZN 4: "prevailing usage" and "usage"

[Wolfgang Lorenz]

Dear Taxacomers,

while trying to fix some controversial names (Coleoptera) I met with the
following problem:
The term "prevailing usage" occurs in several Articles of the new Code (29.5,
33.2.3.1, 33.3.1, 35.4.1, 35.5) and its meaning is explained in the Glossary,
but in some other Articles the word "prevailing" is missing.
E.g.,
Art. 59.3. (replacing Art. 59b of the former 3rd ed.) says that a junior
secondary homonym replaced before 1961 is permanently invalid, but in the new
Code this ruling is mitigated by the words "unless the substitute name is not
in use"...
Does it mean: NEVER used in publications since it's establishment?

Many thanks in advance for your help!

Best regards
Wolfgang Lorenz, Tutzing/ Germany