On Sun, 25 Jun 2017 10:05:23 -0700 (PDT),
wrote:

I am studying a surveyor's map of the neighborhood where I live. The map is on record at the County Clerk's and is known as "the Plat" for my neighborhood. For some of the patios, it notes coordinates for north (or south) and east (or west), relative to some point but clearly not latitude and longitude GPS coordinates. The Plat also gives dimensions of the patios, to the nearest tenth of a foot Written beneath the coordinate numbers is:

(typical)

What does "(typical)" mean in the world of surveying and plats?

I spent a day with the surveyors here. I am not sure how Mason and
Dixon did their job but these days they start by finding "monuments"
(rebar in a small concrete block at grade) designated on the filed
plat. They get a GPS fix on that then start looking for rebar pins on
lot corners. Once they get a bunch in the machine it can pretty much
pinpoint anything they are looking for.
Most of the job is done with the GPS and a metal detector.
Once they pinpoint the lot corners everything is just line of sight.