Add a new menu with a "Copy to Clipboard" action to the About System module. See screenshot. The action can be used to conveniently copy information when reporting a bug etc.
Example of how the copied text looks like:
KDE Frameworks Version: 5.37.0
Qt Version: 5.9.0
Distro: openSUSE Tumbleweed 20170407
Kernel: 4.10.8-1-default
OS Type: 64 bit
Processors: 4 × Intel® Core™ i3 CPU M 370 @ 2.40GHz
Memory: 7,7 GiB of RAM
"About System" dialog with the new menu:
{F3829070}
"About System" with the new menu opened:
{F3829071}
Update 2018-02-04:
BUG: 366266
There will not be a menu but a single button "Copy Info".