question about Arabic: representing foreign words with "v"

Hello.

I live in Israel and most roadsigns here are written in Hebrew,
Arabic and English. I noticed that in some cases when a name of
a street or a city has a "v" sound in it, the corresponding Arabic
inscription makes use of a "nonstandard" Arabic letter: it's
similar to FAA, but has three dots instead of one.

Here is an example: <http://www.geocities.com/schket/zikhron.jpg>.
It's a picture of a roadsign before Zikhron Yaacov interchange
(Zikhron Yaacov is a city in Israel).

I've never seen this letter in Arabic textbooks. It's not mentioned
in web articles about Arabic alphabet either. I would be grateful
if someone could tell me something about this letter, is it commonly
used to represent "v" in non-Arabic words, why is it never mentioned
in textbooks, etc. Are there more letters like this, used to write
foreign words?

It's not that this letter is always used to represent "v". For
example, when "Tel Aviv" is written in Arabic, BAA is used for
both v's.

Many thanks,

leonid

.