Star Trek: 10 Things You Didn’t Know About The Klingon Language
4. Write Like A Warrior
In The Klingon Dictionary, first published in 1985 with a second edition in 1992, Mark Okrand refers to the existence of a "native writing system for Klingon," which he names pIqaD. He goes on to state, however, that the system is "not yet well understood," and so he uses a transcription in the Latin alphabet in the book instead.
The reason for this is that, until recently, Klingon script has been used on screen in Star Trek for decorative purposes only, without any intent to carry meaning. The first few Klingon characters, designed by Matt Jeffries, can be seen on the D7 Battlecruiser in episodes of The Original Series. This was expanded upon for the Klingon 'writing' seen in The Motion Picture.
Michael Okuda was then responsible for The Next Generation-era Klingon graphics (as well as Star Trek VI), but none of what appeared on screen was actually an attempt to write the language. The spoken language of the TNG-Voyager-DS9 era was also…lax when it came to Okrand’s original vocabulary, pronunciation, and grammar and is often referred to disparagingly as Paramount Hol [language] by Klingonists.
Rather mysteriously, a copy of the TNG-Okuda font, with the sounds mapped on, was sent to the Klingon Language Institute (KLI) by an anonymous source at Paramount. This was then developed into a semi-official version of pIqaD, now used by the KLI to write the language in addition to Okrand’s 'official' Romanised orthography. There have been other attempts at writing systems, but that is far too long a story to detail here.
The first time that the Klingon script was used in a way that actually corresponded to the spoken language (and very accurately!) was in season one of Star Trek: Discovery. The Klingons may have looked distinctly dodgy, but a lot of attention was paid to getting the language right.
For the first season of Disco, Netflix provided subtitles in Klingon (even for the English dialogue, although in transliteration, not pIqaD). There are many examples of Klingon script in Star Trek: Lower Decks which also have real meaning and can be translated.