1. Just a little remark to the first two paragraphs. It is not clear what do you mean by “the original Roman majuscules”, because the first were not so beautiful and the imperial (generally considered beautiful) were already used with the interpunct in the inscriptions: http://www.flickr.com/photos/typoblog/461825402/

2. Considering diacritics a subset of punctuation is in my opinion a serious mistake. To my understanding (supported by The Oxford Dictionary) the punctuation “… is used in writing to separate senteces and their elements and to clarify meaning.” (sentence element is a word in this respect). On the other hand, a diacritic “indicates a difference in pronunciation from the same letter when unmarked or differently marked”, i.e. it changes the meaning (sometimes radically) of the word. Punctuation marks are inter-word marks, whereas diacritics are intra-word marks. They have different roles in the communication.

This might seem overly nitpicky to the English reader, but it is a crutial knowledge for those who use diacritics on a daily basis. Also this, quite common, misconception of “diacritics are a punctuation” leads to a serious problems in typefaces where even great typedesigners produce very poor diacritics, because they do not realize that the diacritics are actually parts of the letters. Or they consider the diacritical accents identical to the similarly-shaped/named punctuation (comma accent vs. comma, dot vs. period, macron vs. dash, vertical caron on letters such as d,l,t as an apostrophe, slashed O [Ø] vs. slash + O) thus producing poorly legible texts (in certain languages).

There is definitely more to say about diacritics. Victor Gaultney’s text (mentioned above) and Filip Blažek’s Diacritics project (http://diacritics.typo.cz) are good strating points.

3. Even though, I quite like Kris Sowersby’s typefaces. The word “háček” (meaning caron in Czech) set in Newzald here is not the best example of properly treated diacritics. The caron in particular does not fit the stylistic principles of the letters. My apologies to the author for this comment on his typeface.

Super post.

Regarding T Stein’s comment about the different measures of a typographical point: Actually, as originally proposed by Fournier in his 1764 Manuel Typographique, the definition of a typographical point is 1/72 of an inch:

“At the head of the Table is a fixed scale, which I have divided into two inches, the inches into twelfths, and the twelfths into six of these typographical points, the whole consisting of 144 points.” [note: 144 points over 2 inches. This quote is from Harry Carter’s 1930 translation.]

The problem, of course, is that Fournier’s “inch” had no precise, lawful measurement, but was itself somewhat arbitrary.

The “American Point” system, which used the figure T Stein cites, was established in 1886 by the United States Type Founders’ Association. It was derived from an attempt to reconcile the pica with the metric system by equating 83 picas with 35 centimeters. This yields the 0.0138348 inch point that was used for metal type in the 20th century. With the advent of DTP, the current 1/72 (0.0138888) inch point which we use today was implemented.

On another note, the term “inverted comma” for an opening quotation mark comes from the fact that early in the adoption of the quotation mark (as we know it today), before it was clearly established as a common form of punctuation, a comma was actually turned 180 degrees and placed in the stick upside down to serve as an opening quote mark. The closing quotation mark was an apostrophe, which was already an established form (being basically a raised comma).

One very small nitpickety point: most fonts will probably have no separate glyphs for diaeresis and umlauts, but latin modern (used by LaTeX) does. The diaeresis dots appear higher and with wider spacing between them, the umlaut dots are closer together and lower above the letter, see e.g. in this big pdf file p. 107.

Edit to add: Sorry Jaap, I commented before reading your comment.