COPR (Copyright) is just a claim of copyright...and legally speaking, copyright is not the same as a license for use and distribution (like Creative Commons). You don't want to conflate the two if you really want legal protection (or the appearance of it).
I would recommend putting your copyright statement by itself clearly in a COPR tag:
1 COPR Copyright (c) 2016 Pat Farrell
and put the full actual license text in the NOTEs in the header:
1 NOTE Attribution-NonCommercial-ShareAlike 4.0 International
2 CONT =======================================================================
2 CONT Creative Commons Corporation ("Creative Commons") is not a law firm and
2 CONT does not provide legal services or legal advice. Distribution of
...
I recommend putting the full text of the license in the note because a cross-reference is not likely to be followed or likely even noticed by anyone, and is not the same as actually providing the license to the consumer; and a link could go dead tomorrow. If the license is explicitly in the body of the GEDCOM itself, nobody could claim not to have been informed of the license terms. By claiming both copyright and by explicitly granting a license, you retain your option to sue (i.e., you will have standing) should someone not honor the license.
Disclaimer: I am not a lawyer.