Both the language and layout of signs are worth getting right.
Came across the following notice on a sign along the Wicklow Way at the weekend:
Avoid Erosion. Stay on the path.
Not possible, I'm afraid. You get it, of course, but against all the grammatical odds: because in order to AVOID erosion, you'd actually find yourself walking off the path on the un-eroded ground; and if you STAY on the path you'd never leave it thereby causing a lot more erosion than someone planning to leave at some point after their walk is over. The alternative, "PREVENT" erosion, isn't right either, because in order to do that, you'd really have to avoid walking the Way altogether, and perhaps opt for the No Way. So what they really ought to have on the sign is "Minimise erosion: keep to the path."
On a related matter, and the same walk, it turns out notices with headings saying Notices really bother Mr Digital Spaghetti; and rightly so. He points out that everyone already knows it's a notice cause it's presented in a notice form, in a context that you expect notices to be found. So, it is a sign of pure stupidity and lack of thinking to waste such a valuable part of the medium/message stating the bloody obvious.
(Image from http://funnysigns.atspace.com/s0015.html)