10 things you must remember when doing internationalization of your application:

1. Keep code and content separate.
2. Use Locales.
3. In UI component design, allow for text expansion.
4. Do not concatenate. [Localizing concatenated strings is difficult or impossible.]
5. Do not reuse strings. [The context, meaning, or the space available may change, making localization difficult.]
6. Use re-orderable parameters in strings.
7. Do not use text in graphics. [It all needs to be localizable.]
8. Comment the text strings.
9. Use common components
* Use AVKON component library wherever possible.
* Use StringLoader.h for re-orderable parameters.
* Use CharConv for inbound and outbound character conversions.
* CharConv contains conversion tables for all supported S60 languages and most common encodings.
* Use locale for sorting.
* Use AVKON time and date formatter strings for time/date formatting, or if you need to have new formats, use locale formatters.
10. Follow the formats / templates provided by symbian.