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Setting the primary and secondary character set groups
In the text parts of a MIME message, character set tags, such as US-ASCII or EUC-KR (Korean), specify how IBM® Lotus® Domino® interprets the text data and renders it into recognizable characters. The value that represents a character in one character set can represent a different character in another character set.

When converting a MIME message into IBM® Lotus® Notes® rich-text, Domino uses the information in the character set tags to determine the appropriate characters for representing the message text. Similarly, when Domino converts a Notes rich-text message into MIME, it must determine which MIME character set tag to apply.

On the MIME - Basics tab of the Configuration Settings document, you can define a primary character set group and one or more secondary character set groups. These primary and secondary choices control, among other things, how Domino detects character sets to correctly identify ambiguous text data in a message when converting inbound MIME messages to Notes rich-text and outbound Notes rich-text message to MIME.

Note If your organization sends and receives messages that use US-ASCII characters only, there's no need to change the default settings.

Domino can interpret text represented in 16 different character set groups (also known as language groups) including the Unicode standard for encoding character systems (www.unicode.org/ ). A language group can correspond to a single language (for example, Japanese) or to a region where multiple languages use more or less the same characters (for example, Central Europe). A language group can also support multiple character sets.

For a list of character set groups and the language codes associated with them, see the topic Language codes supported in Notes and Domino.

If the MIME messages your organization receives always contained the correct character set information, there would be no need to change the default settings. However, some mail systems do not provide character set information when sending mail. For example, older mail systems may not support MIME at all, and some Web-based systems enable users to create messages in a given language but don't correctly generate MIME character set information when sending the message. Thus a user sending mail from a Web-based mail system might be able to compose and send messages written in Chinese, but in the sent message, the character set tag US-ASCII is incorrectly applied to the message text. If your SMTP server is configured to use the default character set group, it would be unable to correctly convert this message.

In such cases, Domino examines incoming messages to determine the byte range used and identify unique control codes. It then attempts to match patterns in the incoming message to a probable character set. This process is effective in distinguishing among certain character sets only. For example, it can correctly distinguish messages in the CJKT languages (Simplified Chinese, Japanese, Korean, and Traditional Chinese ) from each other and from an English message), but it cannot distinguish between messages in English or any other Western languages, which tend to use the identical bytes and byte ranges.

To ensure accurate character set detection for the CJKT languages, configure a priority order among the languages by specifying a primary and secondary character. For example, if Domino cannot distinguish whether a MIME message uses EUC-KR (a Korean character set) or GB2312 (a Simplified Chinese character set), it uses the priority order assigned to the primary and secondary character set groups to determine which character set to use in converting the message to IBM® Lotus® Notes® rich-text. Domino chooses the primary character set first, then the secondary character set (in an undefined order -- the order of multiple secondary choices doesn't matter), then the operating system group (for operating systems where the locale can be queried).

When converting outbound messages to MIME format, Domino chooses a MIME character set based on the text of the message. Outbound messages are examined by the Router and the appropriate character set is selected for the message. For example, messages in Japanese are converted using the ISO-2022-JP character set; messages in Simplified Chinese, using the GB character set; messages in Traditional Chinese, using the Big5 character set; and messages in French, using the ISO-8859-1 character set. When Domino cannot automatically detect which character set to use, as with some European languages, it refers to the primary, secondary, and operating system groups, in that order, to determine which character set to use. For example, if all of the characters in a message could be French or Turkish, Domino uses the information about the primary and secondary character set groups to determine which character set to use.

To set the primary and secondary character set groups

1. Make sure you already have a Configuration Settings document for the server(s) to be configured.

2. From the Domino Administrator, click the Configuration tab and expand the Messaging section.

3. Click Configurations.

4. Select the Configuration Settings document for the mail server or servers you want to administer, and click Edit Configuration.

5. Click the Basics tab, and in the field International MIME Settings for this document, select Enabled.

6. Click the MIME - Basics tab.

7. Complete the following fields and click Save & Close:
FieldEnter
Primary character set groupThe character set group for this domain's primary language. English is the default value. Choose the language or region appropriate for your organization, for example, Simplified Chinese.
Secondary character set groupsThe character set groups for other languages typically used in this domain. By default, no secondary character set group is configured. Choose the language or region(s) appropriate for your organization, for example, Western. You can specify multiple secondary character set groups.
8. The change takes effect after the next Router configuration update. To put the new setting into effect immediately, reload the routing configuration.

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