The register is organised by what the work is, not by where or when it was made. A gopuram entry sits beside a coursing entry because the tower stands on the coursing. Six sections cover the tiered gateway, the dry-laid stone that carries it, the pillared hall, the bronze cast for the sanctum, the tank cut to the water table, and the chariot the streets were laid out around.
Every measurement in this register was taken from built work, not from a treatise. Where the two disagree, the wall wins.
Entries are written from measured buildings and from the survey record. Where a figure is disputed, the entry says so and gives the range rather than picking a number. Where a technique is inferred from tool marks or from what survives rather than from a written source, the entry says that too.
An entry carries the prose, the terms the trade uses, the dimensions that constrain the work, and photographs of the thing itself. Nothing in the register is behind a paywall; the standing cost is covered by the principals and supporters listed on the front page.