About being licensed under the CC BY-SA 3.0 ...
The psiKeds XSD is licensed under the Creative Commons Attribution Share Alike 3.0 license. Roughly spoken, your are invited 'to share (to copy, distribute and transmit)' or 'to remix (to adapt)' it, if you '... distribute the resulting work under the same license to this one' and if you respect how 'you must attribute the work'.
... by the
- psiKeds licensing file: https://github.com/dtag-dbu/psikeds/blob/master/000-LICENSING
- CC-BY-SA license file: https://github.com/dtag-dbu/psikeds/blob/master/000-LicenseAddons/licenses/cc-by-alike-3.0.txt
- original CC-BY-SA license file: http://creativecommons.org/licenses/by-sa/3.0/legalcode