Units
Distances stay exactly as the document wrote them. The call table says which unit that is, and a metric tract reports its area in square metres or hectares against the figure the document stated.
Conversion to feet happens once, on the server, when a call becomes a traverse leg. So a metric deed differs from a deed in feet only in the numbers that entered the traverse: placement, DXF output and group offsets are all in the one unit they have always been in.
What is read
Section titled “What is read”| unit | feet per unit | note |
|---|---|---|
| feet | 1 | |
| inches | 1/12 | |
| yards | 3 | |
| miles | 5,280 | |
| rods | 16.5 | a rod is a pole is a perch |
| poles | 16.5 | |
| perches | 16.5 | |
| chains | 66 | Gunter’s chain, the unit the PLSS was surveyed in |
| links | 0.66 | the chain’s hundredth; deeds write “5 chains 25 links” |
| metres | 3937/1200 | the exact US survey foot definition |
| kilometres | 3937/1200 × 1000 | |
| varas | 100/36 | ambiguous, see below |
| arpents | 191.994 | ambiguous, see below |
An unrecognised unit FAILs and names itself. It is never quietly read as feet. Reading varas as feet would draw a parcel 2.78 times too short in each direction and 7.7 times too small in area, and it would close perfectly while doing it. A 100-vara square is 1.7714 acres read correctly and 0.2296 acres read as feet, and both PASS. That is the exact failure the verdict exists to prevent.
The two ambiguous units
Section titled “The two ambiguous units”Some units are a different length depending on where the deed was written. Easting applies a standard, says which, and declines to be quietly confident.
Vara. Applied as the Texas vara, 33⅓ inches, because Texas deeds are where the unit actually appears in US land records. A Mexican California vara is about 33 inches and a Spanish colonial vara about 32.9, which would make a parcel roughly 1% shorter in each direction and 2% smaller in area. That is the size of the area tolerance itself, so the difference can hide inside a PASS.
Arpent. The Louisiana arpent of 191.994 feet, against the Paris arpent of 191.835. The arpent is also an area unit: one square arpent is 0.8462 acres, so “containing 7 arpents” is 5.924 acres rather than 7.
How the assumption gets checked
Section titled “How the assumption gets checked”When the document states its own area, that number either corroborates the applied standard or it does not, and whether the test can tell the standards apart is arithmetic rather than opinion.
If the stated area can discriminate between the candidates, it settles the question and the verdict proceeds normally. If it cannot, the tract is held at REVIEW with the assumption named, so it reaches you instead of hiding inside a badge.