FindFolder argument is a short, not an unsigned short.
Added kLocalDomain and friends.
diff --git a/Mac/Lib/MACFS.py b/Mac/Lib/MACFS.py
index 12d074f..9dbe27d 100644
--- a/Mac/Lib/MACFS.py
+++ b/Mac/Lib/MACFS.py
@@ -15,7 +15,15 @@
kIsAlias = 0x8000
# Constants for FindFolder
-kOnSystemDisk = 0x8000
+kOnSystemDisk = -32768 # previously was 0x8000 but that is an unsigned value whereas vRefNum is signed
+kOnAppropriateDisk = -32767 # Generally, the same as kOnSystemDisk, but it's clearer that this isn't always the 'boot' disk.
+# Folder Domains - Carbon only.
+kSystemDomain = -32766 # Read-only system hierarchy.
+kLocalDomain = -32765 # All users of a single machine have access to these resources.
+kNetworkDomain = -32764 # All users configured to use a common network server has access to these resources.
+kUserDomain = -32763 # Read/write. Resources that are private to the user.
+kClassicDomain = -32762 # Domain referring to the currently configured Classic System Folder
+
kSystemFolderType = 'macs' # the system folder
kDesktopFolderType = 'desk' # the desktop folder; objects in this folder show on the desk top.
kTrashFolderType = 'trsh' # the trash folder; objects in this folder show up in the trash