Bad signage again

I was in Durham for a conference at the weekend and saw this sign on the room where some of the talks were held:

It advises that no food is to be consumed or taken into the lecture room. But if we followed the instructions is gives accurately, we'd starve to death. 

Co-ordination does cause problems, and it's one of those things that people actually aren't very good at getting right. Ewa Dąbrowska, who gave a paper at the conference, has shown that adults, especially those with lower levels of education, can do very badly on tests involving passives and quantifiers. Given sentences like every dog is in a basket or every basket has a dog in it and pictures to match up, they get it wrong a lot of the time. Co-ordination is a different thing, as it's a purely grammatical task rather than a meaning comprehension task, but as I say, people get it wrong a lot. 

So if you're trying to co-ordinate something, the rest of the sentence needs to be grammatical with respect to both parts. If you say Joseph and Mary travelled to Bethlehem, then it is grammatical to leave either co-ordinated part out: 

Joseph and Mary travelled to Bethlehem.
Joseph and Mary travelled to Bethlehem.

Let's do the same with the sign. We need to identify our co-ordinated phrases first:

No food to be [consumed] or [taken into the lecture room].

Now the deletion:

No food to be consumed or taken into the lecture room.
No food to be consumed or taken into the lecture room.

Oh dear. Now we have been instructed not to consume food. At all. Let's try re-bracketing our constituents. Perhaps what's co-ordinated is this:

No food to be [consumed] or [taken] into the lecture room.

Let's try deletion again:

No food to be consumed or taken into the lecture room.
*No food to be consumed or taken into the lecture room.

Oh dear. Now it's not grammatical. We can't say consumed into the lecture room. Another co-ordination fail - add it to the list. I don't know why people don't just keep it simple and say Don't eat in the lecture room.