--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/selections.rst	Mon Jun 29 16:02:28 2009 +0300
@@ -0,0 +1,28 @@
+-*- mode: outline; coding: utf-8 -*-
+
+* MS Windows.
+
+* X Windows.
+
+X11 selection transfers (which both PRIMARY and CLIPBOARD are instances of)
+are done through synthesized X11 events and properties changes.
+
+The messages used to transfer the selections have a maximum size that's
+actually quite low (a few kilobytes).
+
+See
+
+  http://standards.freedesktop.org/clipboards-spec/clipboards-latest.txt
+  http://www.jwz.org/doc/x-cut-and-paste.html
+  http://en.wikipedia.org/wiki/X_Window_selection
+  http://www.emacswiki.org/cgi-bin/wiki/CopyAndPaste
+
+** xclipboard.
+
+The xclipboard command emulates the traditional Macintosh style clipboard by
+claiming ownership of the CLIPBOARD selection and answering any requests for
+its value. When it loses the selection, it immediately asks the new owner for
+the value of the CLIPBOARD selection, makes a local copy, and then reasserts
+ownership of the CLIPBOARD. This way the clipboard contents can persist after
+the original application has exited.
+