Have you noticed that, in various forms used in this India, we capture addresses in varying formats and structures? For example, address fields in Passport form is quite different (in format, structure, and even terms) from those in, say, PAN application form or Voter ID form. That is because we have not yet standardized address structure.
This issue is significant whenever we capture addresses in a database. Of course, we can always have generic address fields. But, that neither allows us to compare one address to another nor it supports automatic address verification against a master set of address database. That means there is absolutely no clean way to say if two addresses are same.
Several countries have standardized addresses and made it completely machine readable and interpretable. For example, in United States, USPS (Postal Department) has gone through extensive exercise to standardize delivery addresses. Zip codes which went from a 6 digit number to a 6+4 system were part of this. Street names, town names, state codes, etc. are all standardized. See an example address (courtesy USPS):
Building have assigned numbers and building types such as apartment, building, etc. were identified by predefined codes (such as APT, BLDG, etc.). See Publication 28 on their website if you are interested!
UPU (Universal Postal union), established in 1874, is the largest physical distribution network. At the time of this writing, there are about 190 countries who are members of this network. UPU has taken effort to standardize the addresses (domestic and international) and the specification, called S42, along with PATL (Postal Address Template Language) are available for various countries to adopt. It is quite extensive and talks about next generation addressing including "Geo" addresses. Countries are expected to create a template for specific use and mapping those template fields to the S42 standard fields. This specification is quite detailed.
Indian postal department is a member of UPU and is on its way to create next generation addressing and extended pin codes. It may take few years to come to effect. But, we are absolutely in the right path. And as we implement this huge UID database with billion plus addresses, we surely need to be aware of these.