This should help taichi...
Having your photo certified
If you are not required to provide an up-to-date UK or other EEA passport, UK travel document for identity purposes, or, If you’re providing identity documents other than an up-to-date UK or other EEA passport, UK travel document, you must get an authorised person to sign the back of your photo. This person must have known you personally for at least two years, must not be related to you in any way, and hold a NI driving licence which has been issued after 1 April 1999. The person signing your photo must also complete section six of your DL1 form. DVA will make random checks on people who sign photocard driving licence applications.
The person signing your photo must
live in the UK
know you personally (for at least two years)
not be a relative
Suitable people include
lay magistrate or Justice of the Peace
a minister of religion
a professionally qualified person, for example, a lawyer, teacher or engineer
a librarian
a local business person or shopkeeper
a local councillor, MP, MLA, MEP or MSP
a bank or building society officer
an established civil servant
a police officer