Add explicit note about grace period vs. DOSP

dosp-survey.ltx

@@ -281,6 +281,12 @@ Initiative, it appears to us to be compatible with the Open Source
 Definition, and --- unlike BUSL, for instance --- is claimed by its
 authors to be a form of open source licensing.
 
+One way to view the distinction between delayed open-source licensing and
+grace period reciprocal licensing is that the former aims to compromise
+between proprietary and open source licensing, where the latter aims
+to compromise between permissive and reciprocal licensing --- in both
+cases by modifying the license terms after a delay.
+
 \numberedsection{Other Terminology and Practices}\label{terminology}
 
 We've encountered a number of other terms that can describe DOSP or