What is the naming convention used for US blockgroups codes?

Question

I was looking at the naming convention for US blockgroups but could not find and reliable documentation for it. US Census website mentioned somewhere that the 5 digit US county code can be split as XXYYY where XX denotes the state code and YYY denotes an the county id within that state. Is there a similar convention for US blockgroups as well? I believe they use the FIPS system but wanted to get some more information on that.

Alternately, is there a source where I can get naming conventions for all these geospatial types?

Answer 1

Yes indeed, block groups are formatted like:

SS CCC TTTTTT G

where S = State, C = County, T = Tract, and G = Block Group. Blocks have an additional three digits beyond that.

Reference: https://www.census.gov/geo/reference/geoidentifiers.html *click on "GEOID Structure for Geographic Areas".