Translations:Help:Extension:Translate/Page translation administration/32/en

Variables. It is possible to use variables similar to template variables. The syntax for this is $code1contents$code2. For translators these will show up only as $code3, and in translation pages will automatically be replaced by the value defined in the translatable page (so they are global "constants" across all its translation pages). Variables can be used to hide untranslatable content in the middle of a translation unit. It also works for things like numbers that need to be updated often. You can update the number in all translations by changing the number in the translatable page source and re-marking the page. You do not need to invalidate translations, because the number is not part of the translation unit pages.