Thanks Ray, for this tipp. 

However, the user experience is not yet entirely consistent and therefore user-friendly. For example, I have to go first to the knowledge base, copy the clipboard content, go back to the record I want to use it in, open the Log note in full composer view and paste it. This is quite confusing and would be very nice if implemented consistently. For E-Mails also differently  - inside chatter it copies without format and in the full composer it takes the formatted content of the clipboard section and it can be even pushed directly from the clipboard button.

This is already supported.

1. From the Knowledge Clipboard you want to use, select the generic Copy button:

2. From Send Message, Log Note, Full Email Composer, WhatsApp, etc, use one of:

• browser paste feature -- ie: Right click -> Paste
• keyboard -- ie: CTRL + V (windows) or Control + Y (mac)
• windows paste -- ie: WIN + V -> select snippet