Hey Jakub, by Localization do you mean time and date settings on the phone? I am kind of uncertain as to what exactly you mean. If that is the question then you can select the appropiate time zone and date for the phone.
Current in the admin guide it is only supported on the spa525g model. As of an estimated time or if they will ever have this available for the spa502g, I am not certain if they will or when. Hope this Helps.
Regional Tab 233
Call Progress Tones 233
Distinctive Ring Patterns 236
Control Timer Values (sec) 237
Vertical Service Activation Codes 238
Vertical Service Announcement Codes 243
Outbound Call Codec Selection Codes 243
Time (Cisco SPA 525G/525G2 Only) 246
Language (Cisco SPA 525G/525G2 Only) 246
this is great news, thank for your prompt attention to this matter.
File already loaded into the phone, fully correct, I recommend to all,