Translation guidelines for user interface text

Here are basic guidelines which can be good starting points in translating Drupal to your own language. The advice from "Linux for Schools: Localization and Translation" is a good point to consider:

Your task is ... to convey the content, so do not be afraid to localize the original text with something completely different (something that fits, of course). Read the original text, understand its content, and consider how you would formulate the text in your language (without first having heard of the original text).

To find individual tasks and roles related to translating user interface text on localize.drupal.org, visit the Contribute to translation page.

Be consistent

It is easier to understand Drupal if translators manage to be consistent with the use of words. If you translate a word with different synonyms throughout Drupal, it is difficult for people to understand that you are talking about the same functionality. To achieve this consistency throughout a whole Drupal site, a word list for words that occur in Drupal's strings is recommended. The English-Norwegian word list for Drupal provides a good example of how this is done. If you create your own word list, then the whole translator community of your language can discuss the standardization of Drupal words and expressions into your language. It will be helpful to not set up a new word list, but re-use existing ones from an existing translation project.

It is also important to be aware of the writing style of the localization files. If your translation project has started a conservative and formal style, stick to it. If the style is more colloquial, then follow that style. Feel free to also rewrite existing translations if you think you can formulate them better, but try to stay to the same writing style for consistency.

Be accurate

Translate internet terms and technologies and refrain from using the English equivalents. If you are not sure of the equivalent word in your language, try contacting the language departments of respectable universities in your country or a state bureau who takes care of your language. Do not be afraid to use or introduce new terms as long as they are standardized. Remember, when the word "mouse" was introduced (for that hand-controlled device for interacting with a computer), most people thought it was ridiculous.

Leave placeholder text as is

Placeholder text represents data that will be inserted later. You may notice things like "@something", "!something", or "%something" in the text you are translating (e.g., "Size: !size"). These "placeholders" represent data that will be inserted in that spot when the page is generated. When you are translating text, be sure to include the placeholder exactly as it was, so that the data will still be inserted in your translation (e.g., "Tamaño: !size").

Additional thoughts

Other areas which need guidelines will differ from language to language. Please get in touch with the maintainers of your language's translation team or contact your community specific to your language.

References:
Drupal Norge's handbook page on contributing translations
Linux for schools: Localization and Translation
Danish guide for translators of free software