You are looking at many info about darkness

Darkness can now befall cow.

Any location with a material of '_dark_' will hide all objects (including all exits from the location) and display some additional text 'It is dark here'.

Any objects with a material of '_light_' will illuminate the room as if it were not dark. It will have '(that is lighting this place)' after it.

Any objects in a dark location that are posed as glowing or have material _glowing_ will be seen regardless of there being a _light_ in the location.

You can, however manipulate any object in a dark room even if you cant see it.. so typing exit will take you out of a room if there is an exit even if you cant see it due to darkness.

You can customise the messages shown by changing these 2 pocket variables using the manipulate cowmand:
darkmsg=
lightmsg=

eg: a fridge you can go into could have its pocket set to 'darkmsg=Ah.. the light does go off when you close the door'

Another example, a lantern could have 'lightmsg=casting a warm glow'

If you want to hide the additional message simply set it to a single space eg 'lightmsg= '

There are 2 new variable you can use:
$loc_dark= 1 if the location is dark.

$loc_lit is a number indicating how lit the location is, 1 for every _light_ object. The location itself sets this to -1 to start with so:

$loc_lit < 0 is a dark unlit location
$loc_lit > 0 is a lit location, no indication that the location is dark
$loc_dark = 1 indicates that the location is dark regardless of lights.

Under development:
The display of objects in a dark location is not completely correct as yet. Hosted but glowing objects dont look right, not do glowing objects with hosted dark objects.. and the divisions between many non-glowing objects are showing.