A postal village is generally a community, settlement, or hamlet (place) that has a post office and is designated as such by the postal administration. It may be seen as a rural neighbourhood.
This term seems to have been most common in the latter half of the 19th century when it was in common use in maps and gazetteers, variously abbreviated p.v., P.V., PV, and p-v. The term is generally used for a community within a township (rural region) as opposed to an incorporated village or other municipal government. By establishing a post office in a particular community it receives official recognition, often for the first time, for a name, an important step in the development of any community.
References
Postal village Wikipedia(Text) CC BY-SA