--- a/NEWS Mon Dec 22 15:50:16 2014 +0100
+++ b/NEWS Mon Dec 22 16:44:24 2014 +0100
@@ -244,6 +244,14 @@
* Support for Proof General and Isar TTY loop has been discontinued.
Minor INCOMPATIBILITY.
+* System option "pretty_margin" is superseded by "thy_output_margin",
+which is also accessible via document antiquotation option "margin".
+Only the margin for document output may be changed, but not the global
+pretty printing: that is 76 for plain console output, and adapted
+dynamically in GUI front-ends. Implementations of document
+antiquotations need to observe the margin explicitly according to
+Thy_Output.string_of_margin. Minor INCOMPATIBILITY.
+
* Historical command-line terminator ";" is no longer accepted. Minor
INCOMPATIBILITY, use "isabelle update_semicolons" to remove obsolete
semicolons from theory sources.