Hi Melanie!
I have done some research for you and dug up this info:
region flag meaning
0x00000001 Allow damage (llSetDamage() will work)
0x00000002 Allow landmark creation (region-wide)
(this will turn on the menu option)
0x00000004 Allow set home (region-wide)
(this will turn on the menu option)
0x00000008 When teleporting from here, set the home position
to the teleport destination (Orientation island)
(this is set from god tools window)
0x00000010 Region sun is fixed
0x00000020 Region is free of all charges/taxes
(this applies to tier charges, not used in viewer)
0x00000040 Region doesn't allow terrforming
0x00000080 Region doesn't allow land sale
0x00000100 Region is a sandbox (wipe all content at 0:00)
0x00000200 Draw region tiles in world map view even if the
map is too small (sets the draw threshold to 2 pixels)
0x00000400 Not used in viewer (disable all agent interaction)
0x00000800 Not used in viewer (purpose unknown)
0x00001000 Disable collisions (Estate settings)
0x00002000 Disable scripts (Estate settings)
0x00004000 Disable physics (Estate settings)
0x00008000 Region can't be seen into from neighbors
0x00010000 Deprecated visibility flag for mainland (commented in viewer)
0x00020000 Allow public access
0x00040000 Don't count traffic
0x00080000 Block flight
0x00100000 Allow direct teleport
0x00200000 Estate level script disable
0x00400000 Block push
0x00800000 Deny no payment info on file
0x01000000 Deny payment info on file
0x02000000 Deny payment info used
0x04000000 Allow parcel join/divide
0x08000000 Send abuse reports to estate owner email
0x10000000 Allow voice
0x20000000 Block "Show in search"
Predefined estate IDs
1 Mainland
2 Orientation islands
3 Linden internal
4 Showcase
5 Teen grid
Please note that the menu items are enabled and disabled on the estate level,
but the functionality is enabled through parcel flags. That means you may have
the menu option available, but get a message that you're not the parcel owner
when you try to use it.