In german Lesezeichen is fine for external links and internal bookmarking.
It catches the spirit.
And: Lesezeichen is already used everywhere in wt (block on my webtrees/homepage and menu). The block is named Lesezeichen and at the bottom of the block it is “Neues Lesezeichen hinzufügen”, the menu is called Lesezeichen, only the last menu item is called “Zu Favoriten hinzufügen”. Obviously this decision has been taken some time ago and i guess german users are used to it. So we shouldn’t rewind everything to oldstyled “Favoriten”, better rename the isolated and confusing menu item.