[Grammar] "Keep door closed at all times"

[ashsmith]

I got a sign says "Keep door closed at all times"
some one said the grammar is wrong in it. says there should be "the" in that sentence.
I tried searching abit I found out that this is similar to "stick no bills"
So I guess in request forms the grammar doesn't matters. In signs or boards how do I explain this, like is there a rule in english for these type of things?
Thanks

 

[emsr2d2]

I got a sign says "Keep door closed at all times"
some one said the grammar is wrong in it. says there should be "the" in that sentence.
I tried searching abit I found out that this is similar to "stick no bills"
So I guess in request forms the grammar doesn't matters. In signs or boards how do I explain this, like is there a rule in english for these type of things?
Thanks

Usually on signs, space is at a premium (the more words you have and the more space they take up, the more they cost) so words that aren't completely necessary are sometimes left out. That is the case with the sign you mention. Technically, it should read "Keep this door closed at all times", but the "this" isn't vital.

The same applies to, for instance:

Keep Clear - Access Required

If this were a full sentence, it would say "Keep this area/space clear because access is required [at all times]" That would be a very big sign!