Web User Interface

System → User Preferences → General User Settings → Phone Language

Phone User Interface

User Settings → Preferences → Language

XML Configuration

<user_pref>

<language>VALIDVALUE</language>

</user_pref>

Description

Set the Phone LCD language: 

en (English),
fr (French),
es (Spanish),
it (Italian),
pt (Portuguese),
nl (Dutch),
de (German),
el (Greek),
ru (Russian),
tr (Turkish)

Valid Values

en, fr, es, it, pt, nl, de, el, ru, tr

Default Value

en