The use of different symbols for opening and closing quote is just a common typographic style. See Wikipedia: Quotation mark - Electronic documents - Typewriters and early computers:
Typographically, there are two types of quotation marks:
'…' and "…", are known as neutral, vertical, straight, typewriter, or "dumb" quotation marks. The left and right marks are identical.
‘…’ and “…”, are known as typographic, curly, curved, or book quotes. The left (start) and right (end) forms are different, resemble small figures six and nine raised above the baseline (like 6…9 and 66…99), but then solid, i.e., with the counters filled. In many typefaces, the shapes are the same as those of an inverted (upside down) and normal comma.
The second ‘…’ typographic style is the one used in man pages.
A similar style is used for double quotes in Latex, except the ` and ' characters are repeated twice to signify the double quote:
``You were a little grave,'' said Alice.
fstab
man page, a couple paragraphs down, under the heading "The first field." I tried to blockquote it here, but it got all messed up due to the backticks themselves. No I can't see that button for the problem solution btw..where did it go?