The context does go further than a postcode though Doodledog. This is from unifrog.
"Typical criteria for contextual offers
Not all UK universities make contextual offers. For those that do, each one sets its own criteria, but they usually include a few of the following:
You have a disability
If you have a physical or non-physical disability, you may be eligible for a contextual offer.
You’re a young carer
A young carer is anyone who - unpaid for - cares for a friend or family member who cannot cope without support due to illness, disability, a mental health problem, or an addiction.
Your school’s overall academic performance
If, for example, the performance of your school, college or sixth form is lower than the national average, your academic performance so far might be given special consideration.
You’ve been in care
This means you’ve spent time in local authority care. Very often, you’ll need to declare that you’re a care leaver on the UCAS form and have it confirmed by your referee.
You’re a first generation Higher Education attendee
This means that you’re the first in your immediate family to attend university. Your parents therefore, did not attend university.
You have a lower family income, or live in an area with a lower socioeconomic status
You might be entitled to discretionary payments or free school meals at school/college. Schools also assess whether you live in an area with a lower socioeconomic status using the POLAR or ACORN postcode search. POLAR and ACORN are both classification tools which provide data on young people participating in higher education."