Thanks for the quick answer. How is the documentation for this going to be managed? Is it expected that everyone should be using the latest version of the software and the documentation isn't up to date yet?

It is going to take this old dog a long time to learn this new trick. I've been using Ctrl + L for a long long time.

Great, good to know. Now how do I change it back?

there is an add-on @ https://addons.mozilla.org/en-us/thunderbird/addon/dorando-keyconfig/ for custom keyboard shortcuts, but I'm having difficulties configuring it... I think this is a no-go to adapt TB shortcuts to the ones of Office. Office users mostly use Outlook anyway, not TB, so... My suggestion for the next release: contextual sensitive shortcuts: • Ctrl-K leave it as «insert link» • Ctrl-L restore shortcut as «insert link» if text is selected in the editor (now, nothing happens). If an e-mail is selected in the list, then Ctrl-L forwards the e-mail as it does now (Ctrl-F can't be used because it stands for «find»).