What I did 2day

http://www.bbc.co.uk/blogs/writersroom/2011/10/new_script_merlin_-_the_wicked.shtml

http://www.bbc.co.uk/iplayer/episode/b01692qr/Merlin_Series_4_The_Wicked_Day/

Basically I looked at the script of Merlin and saw the EXT and INT.
Ext means exterior which is outside in a scene and interior means inside  in a scene.
We read the script of Merlin and then watched the episode. After that we stopped the video after every time the scene changes and we looked back to the script to show if it's ext or int.
If the scene is interior and exterior it will show ext/int on the script and then the location.
I could use this in my film by writing ext/int whenever the scene is inside or outside. Also the text is simple and gets straight to the point. This is easy for everyone to read