Persian decimal separator

From: Roozbeh Pournader (
Date: Wed Nov 15 2000 - 18:41:21 EST

Dear All,

Some time ago, there was a discussion here about the Persian decimal
separator. I am posting a short report about our queries into different
Iranian bodies. Sorry for the long and somehow formal thing, but it seems
important to us.
I'm still waiting for responses from Iranian Academy for Sciences (IAS),
and Iranian Mathematical Society (IMS). I have answers from these sources:
* Iranian Academy for Persian Language and Literature (IAPLL);
* Iranian Standards and Industrial Research Institute (ISIRI) which is
  the national standard body;
* Iran University Press (IUP), and Fatemi Publishing Institute (FPI),
  which are the largest and highest quality academic publishing houses
  in Iran.
I think that IMS will answer the same as FPI, since they seem to use the
same conventions in their books that is not published by any of these two
houses. They certainly use the house rules when they publish with one of
these two, but not with other houses.
I also add our conclusions, as current representatives of HCI (Iranian High
Council of Informatics) in text encoding issues which is the responsible
body for national computing related standards, which is transfered to it
from ISIRI.
1. All sources agree that slash and decimal separator should be considered
2. ISIRI has a character set in their standards (ISIRI 3342, the
   rarely-used national standard) which distinguishes the two characters,
   while not distinguishing hyphen from minus or colon from division sign
   (of which the latter case is really weird). They did not give any
   special comments regarding the standard, since the standards commitee
   for the character set issues is dissolved for a long time, and the
   responsiblity was handed to the HCI. The standard shows the glyph for
   the decimal separator as described in 4. They have also another
   standard (ISIRI 2901-revised:1994) for keyboards, that distinguishes
   the two characters.
3. IUP and FPI already use the same publishing software that distinguishes
   these, for more than five years, and IUP has distinguished them even
   before that time. They both agree that the the sequence ONE SLASH TWO
   means 0.5 and not 1.2. They specially say this because of the need for
   clear interpretation of in-text formulas. (IAPLL sees this
   interpretion lying beyond its competence, and refered us to the IAS.)
   IUP has also published a scientific style guide which explicitly
   mentions the difference, and asks for a glyph shape described in the
   last part of the next item (I can provide you with copies of the page
   mentioning this. We also use software that distinguishes these.
4. All except IUP agree that the glyph shape for the decimal separator
   should be a shortened, lowered and possibly more slanted slash. But
   IUP has changed the default behaviour of the mentioned software to
   use a glyph exactly similiar to the isolated form of REH (U+0631)
   for the decimal separator. This has been the case even in their old
   books, before their adoption of computer software for publishing.
   But the IUP recommendation in this case is considered old tradition
   by others, including us, and not acceptable. (I can provide digital
   images of text produced by FPI, IUP, and ourself.)
5. All except IUP agree that in the case of lacking decimal separator
   in the software, a slash is the best substitute. IUP prefers the
   REH shape in all cases. FPI insisted that using the slash for both
   division and decimal separation is unbearable, and told that in the
   case of a lacking decimal separator glyph, all the text should be
   scanned for use of slash as division sumbol, and those cases transformed
   to two dimentional fractions.
6. In the case of missing Persian shape for the decimal separator,
   IUP and FPI (and also us) prefer the Arabic shape over the slash.
   IUP may also prefer the Arabic shape over their REH shape, but that's
   not verified yet. IAPLL prefers the slash over the Arabic glyph.
7. All sources agree that for date separation, one should only use the
As final conclusion:
  In case of information interchange, when the character set permits,
  a decimal separator (U+066B) is certainly prefered to a slash (U+002F)
  and must be used. Computer programs should render the Persian U+066B as
  a shortened, lowered, and possibly more slanted slash; this should be
  distinguishable from the slash at the first sight (I can provide
  examples). If the Persian shape is lacking, if the text context is
  mathematical, the Arabic shape must be used. In other cases, the slash
  shape is acceptable (but will be considered illiterate or
  nonprofessional, somehow similiar to using spaces instead of zero width
(We have not yet received enough responses to our queries about the
thousands separator, but it seems that there will be a lot of disagreement
about this. I can only tell that the national character set and keyboard
standards, ISIRI 3342 and 2901 mentioned in section 2 above, distinguish
the thousands separator from comma, apostrophe, etc. The glyph shape
is similiar to the shape seen in the Unicode charts for U+066C).


This archive was generated by hypermail 2.1.2 : Tue Jul 10 2001 - 17:21:15 EDT