TYPO3 v8 has reached its end-of-life March 31st, 2020 and is not maintained by the community anymore.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
Modeling Cross Cutting Concerns¶
A cross cutting concern we are talking about here is a problem that has to be solved at multiple, distinct places within the system that have no further connection to each other. It is a cross class-hierarchy and maybe cross-extension problem and can and should not be solved with class abstractions.