• I have tested the latest master version from http://builds.jabref.org/master/ and the problem persists

JabRef version
JabRef 5.0-dev--snapshot--2018-10-09--master--29838ee59
Linux 4.15.0-36-generic amd64
Java 1.8.0_181

Steps to reproduce:

1. select an entry
2. display preview (alt+2)
3. copy preview (ctrl+shft+C)
4. paste preview

The result is tagged with HTML tags. In most situations, like pasting to a word-processor or editor, I don't want these.
Also, it's not possible to just select the previewed entry and copy it using the OS cut-n-paste system.

Please stop the "copy preview" command that putting HTML into the output. Just plain text into the paste buffer.
Another command which behaves as the present "copy preview" may be retained if there's user-demand.

Thanks!