The American Physical Society (APS) provides PhySH under the public domain Creative Commons CC-0 1.0 license: https://creativecommons.org/publicdomain/zero/1.0/
This means that APS waives all rights to PhySH under copyright law. Anyone is free to copy, modify, redistribute or otherwise make any use of these physics concepts and their relationships and identifiers.
The name “PhySH” may not be used without express permission from American Physical Society.