Wrap translatable strings with `_()` e.g. `_('string to translate')` and the `i18n-scan.pl` and friends will correctly identify these strings as they do with all the existing translations.
If you have multi line strings you can split them with concatenation:
```js
var mystr = _('this string will translate ' +
'correctly even though it is ' +
'a multi line string!');
```
You may also use line continuations `\` syntax:
```js
var mystr = _('this string will translate \
correctly even though it is \
a multi line string');
```
Usually if you have multiple sentences you may need to use a line break then use the `<br />` HTML tag:
```js
var mystr = _('Port number.<br/>' +
'E.g. 80 for HTTP');
```
To simplify a job for translators it may be better to split into separate keys without the `<br />`:
```js
var mystr = _('Port number.') + '<br/>' +
_('E.g. 80 for HTTP');
```
Please use `<br />` and **not**`<br>` or `<br/>`.
If you have a link inside a translation then try to move its attributes out of a translation key like:
```js
var mystr = _('For further information <a%s>check the wiki</a>')
This will generate a full link with HTML `For further information <a href="https://openwrt.org/docs/" target="_blank" rel="noreferrer">check the wiki</a>`. The `noreferrer` is important when making a link that is opened in a new tab (`target="_blank"`).
### Translations in LuCI lua+html templates
Use the `<%: text to translate %>` as documented on [Templates](./Templates.md)
### Translations in Lua controller code and Lua CBIs
As hinted at in the Templates doc, the `%:` is actually invoking a `translate()` function.
In most controller contexts, this is already available for you, but if necessary, is available for include in `luci.i18n.translate`
## Translation files
Translations are saved in the folder `po/` within each individual LuCI component directory, e.g. `applications/luci-app-acl/po/`.
You find the reference in `po/templates/<package>.pot`.
The actual translation files can be found at `po/[lang]/[package].po`.
In order to use the commands below you need to have the `gettext` utilities (`msgcat`, `msgfmt`, `msgmerge`) installed on your system.
On Debian/Ubuntu you can install with `sudo apt install gettext`.
