enckse [1] filed a deletion request for opensc-0.15 [2]: This appears to just be a versioned (obviously 0.15) copy of opensc. 0.15 is still in the archive[0] if someone did want to install the specific version...though regressions/bugs that cause a user to want to downgrade should be reported to the project (opensc has updated/changed a lot since 0.15).
https://archive.archlinux.org/packages/o/opensc/ [1] https://aur.archlinux.org/account/enckse/ [2] https://aur.archlinux.org/pkgbase/opensc-0.15/
