Q:

Strategy for defining Unicode Ranges by Culture

I am new to Unicode have been given the requirement to look at some translated text, iterate over all of the characters of that translation and determine if all the characters are valid for the target culture (language and location).  
For example, if I am translating a document from English to Greek, I want to detect if there are any English/ASCII "A"s in the Greek translation and report that as an error.  This may likely be the case from corrupted data from a translation memory.
Is there any existing grouping of Unicode characters by culture?  Or is there any existing strategy for developing this kind of grouping?  I see that there is some grouping of characters at (http://www.unicode.org/charts/).  But it seems that this is not quite what I am looking for at first glance.
Does any thing exist like "Here are the valid Unicode characters for Spanish - Spain: [some Unicode range(s)]"  or "Here are the valid Unicode characters for Russian - Russia: [some Unicode range(s)]"
Or has anyone developed a strategy to define these?  
If this is not the right place to ask this question, I would welcome any direction on where might be a good place to ask the question.

A:

This is something that CLDR (Common Locale Data Repository) deals with. It is not part of the Unicode Standard, but it is an activity and a resource managed by the Unicode Consortium. The LDML specification defines the format of the locale data. The Character Elements define some sets of characters: “main/standard”, “auxiliary”, “index”, and “punctuation”.
The data for Greek includes only Greek letters and some basic punctuation. This, like all such data at CLDR, is largely subjective. And even though the CLDR process is meant to produce well-reviewed data based on consensus, the reality is different. It can be argued that in normal Greek texts, Latin letters are not uncommon, especially in technical areas. For example, the international symbol for the ampere is “A” as a Latin letter; the symbol for the kilogram is “kg”, in Latin letters, even though the word for it is written Greek letters in Greek.
Thus, no matter how you run the analysis, the occurrence of Latin “A” in Greek text could be flagged as potentially suspicious, but not an error.
There are C/C++ and Java libraries that implement access to CLDR data, as part of ICU.

