texlive-specs-x from openSUSE:Leap:42.3 project
Select Your Operating System
Add repository and install manually
For standard run the following as root:
zypper addrepo https://download.opensuse.org/repositories/openSUSE:Leap:42.3/standard/openSUSE:Leap:42.3.repo zypper refresh zypper install texlive-specs-x