This is from the Boker site;
Are all of your knives manufactured in Germany?
No. Boker USA, Inc. carries several different brand names, which are manufactured in various parts of the world. Please refer to the list below:
◾Boker knives: Solingen, Germany
◾Boker Arbolito knives: Argentina
◾Boker Plus** knives: Taiwan and China
◾Cinch knives by Boker: Solingen, Germany
◾Magnum knives: Taiwan and China
https://www.boker.de/us/faq.html
** Also, Boker has contracted with an Italian firm to manufacture a so called "premium" line of the Plus family.
"Tree Brand" is not currently used.
The bottom line, if it has a tang stamp of Solingen, it's wholly manufactured in Germany...a tang stamp stating Germany only means the knife was wholly or partially assembled in Germany of parts coming from outside of Germany, or in some instances, completely assembled elsewhere using some parts manufactured in Germany;
Solingen = 100% German made.