This article is using Klingon symbols known as pIqaD. It is possible that some devices do not display them correctly.
pIqaD
pIqaD letters
A clock using Klingon digits:
The word pIqaD (pronunciation: S) refers to the klingon letters. According to The Klingon Dictionary, it is a "native writing system for Klingon" and "is not yet well understood"(1). Meanwhile, it has become the name for a specific set of used Klingon letters. Many Klingonists use the name pIqaD to refer to an arbitrary correlation of Klingon style symbols fitting to the alphabet used in The Klingon Dictionary.
The mapping is very cleverly done... I think it is great, it makes it so you can write the language... I wish I could read it, when I get something written in pIqaD I'm able to very slowly figure it out... I am glad someone really is doing it and has decided that it is an alphabet and not a syllabary. Now we know, cause Michael Okuda and I didn't know that.
Appearance
Through the years, this "KLI pIqaD" has been used by many people in many non-canon publications, and it even has been used in several canon sources. Marc Okrand brought the galleys of the Haynes manual to qep'a' in Chicago in order to ask a few people who could read it well to look over the pIqaD. One may qualify that as accepted by Okrand.
Some Klingonists do not like the fact that several symbols resemble their Terran counterpart quite well, such as D (d) looks like a Greek delta, l (l) looks like L, but even more that the apostrophe really looks like an apostrophe: z(6). From a Klingon point of view, the apostrophe is treated as a single letter, so it could be any kind of symbol.
Similar letters
With some of the fonts, q and Q are very hard to distinguish: compare k and q. This can sometimes also happen with ng and o (f and o) but these are easier to distinguish due to the Klingon phonology, as one is a consonant, the latter is a vowel.