Map/Reduce Views in Couchbase 2.0 involve understanding Unicode Collation ordering of letters, which differs from Byte Order (like ASCII) and groups letters by case rather than a range of all Uppercase or Lowercase. Non-English accented characters follow a similar principle, with certain combinations occurring before others. When determining startkey and endkey ranges for strings in Couchbase Views, it's essential to consider this ordering to ensure accurate results. For example, querying Breweries by_name using the beer-sample database may return different results depending on whether the query starts with Uppercase Y or Lowercase y, highlighting the importance of understanding Unicode Collation. Understanding the nuances of Unicode Collation can help developers optimize their range queries and achieve more accurate results in Couchbase Views.