Edge Description

Why is it common to use “Reeded” for the edge of coins when the COA from the mint uses “Milled”

Surely the Mint knows the correct term.

I suggest only using “Milled” in future - especially for coins from the Royal Mint as they never use “Reeded”

Vern

Milled doesn't say anything about the form though only that a watermill (at least that's where the word came from) was used to produce the edge.
 

• mill: 1550s, "subject to mechanical operations carried on in a mill;" 1560s, "to grind in or as in a mill, reduce to fine particles;" from mill (n.1). Meaning "to flute the edge (of a coin, etc.) is from 1724. Related: milled; milling.

• reeding: Formed with channels and ridges like reeds, as the edge of a coin.

Nope, always use reeded to describe a reeded edge, don't use the word milled, that belongs in Technique.

The mint can say milled edge, but we are describing the effect they produced when they milled the coin.

In this case, reeded, but other effects are also milled; segmented reeding, slanted reeding, and so on.

(edit)

From the guidelines:

• Reeded, for edges with evenly distributed grooves around the entire circumference. Specify the number of grooves and if the grooves are incuse or tilted. Note that reeded edges are known as ridged in American English and milled in British English.

For consistency, if an American uses the word Ridged or a Brit uses Milled, replace them with Reeded.

Agreed. I prefer reeded, not milled. It's a matter of description, terminology preference and definitions but describe the same thing.  Brits tend to favor milled, in the U.S. reeded. 

I use "Reeded" which is in line with the below guidelines: https://en.numista.com/catalogue/edges.php

Also, worth noting RM does recognise the term reeded, under milled: https://www.royalmint.com/discover/coin-collecting/coin-collecting-glossary/

It seems they use the term for simply any coin with a patterned edge produced by machine. For example, it lists the new £1 as milled despite it clearly being segmented in partially milled (reeded) and partially blank.

Numista has laid out guidelines for the different types of edges.

RM probably hasn't changed terminology because all our coins are either plain, lettered, or reeded - or a combination thereof. We don't seem to have different edge patterns, but other mints do.

So, both would say the technique is milled. However, as the RM doesn't produce different designs, it also uses the term to describe the pattern. Numista doesn't, and provides greater detail.