Updated README

README.md

@@ -3,7 +3,13 @@ Ebuild overlay for Gentoo Studio (http://gentoostudio.org)
 
 All ebuilds:
 * use EAPI7 or higher
-* are any of: not in the main portage tree, differ from the main portage tree version in some significant way, a later version than in Portage
+* are any of: 
+	* not in the main Portage repo
+	* differ from the main portage tree version in some significant way
+	* a later version than in Portage
+
+Some ebuilds may have been copied from other overlays, such as audio-overlay or nedko's LADI overlay.
+The reason for this is catalyst (the software used to build the install tarball) can only have one overlay.
 
 To use this repo, edit /etc/portage/repos.conf/gentoostudio.conf: