Notes within element definition pages (e.g. http://www.tei-c.org/release/doc/tei-p5-doc/en/html/ref-cb.html) disappear when switching to another language (e.g. http://www.tei-c.org/release/doc/tei-p5-doc/de/html/ref-cb.html). This is a serious problem and I suggest to disable the entire translated Guidelines versions until this is fixed.
This is actually a misunderstanding. Notes appear in the target languages if they exist -- see for instance:
http://www.tei-c.org/release/doc/tei-p5-doc/fr/html/ref-cb.html
The note has been translated into French, but not into German. The question is what should be done about this; to me it makes more sense to display the English note where there is no German note, but the current system displays nothing.