Wikipedia alphabet approach would miss exotic expressions such as music-n [1] / nyquest [2] ; ANIMAL [3] ; iterative/generative/decorative forms such as haskel / arc
[1] https://en.wikipedia.org/wiki/MUSIC-N
[2] https://en.wikipedia.org/wiki/Nyquist_(programming_language)
[3] https://en.wikipedia.org/wiki/ANIMAL_(image_processing)
The "Q-expression" terminology, as far as I can tell, exists only in the "Build your own Lisp" project. They are an object type deeply in integrated into the run-time with its own tag. An expression object type tagged as a Q-expression rather than an ordinary expression is treated as a self-evaluating object by the evaluator.
It's a different approach to quoting, in a dialect that doesn't use Lisp-like lists for representing the program and uses if/else ladders in C that call strcmp to identify and dispatch operators instead of implementing symbols, an iconic feature of Lisp.
In the 1970's, the MDL language (pronounced "muddle") featured two kinds of cons objects with different type tags, both capable of representing list structure. One had a printed notation with angle brackets to distinguish it and give it print/read consistency. The angle bracket forms were given different semantics. See HN discussion here [2019]:
https://news.ycombinator.com/item?id=19700045
MDL made parenthesized expressions self-evaluating like (1 2 3) -> (1 2 3), while the angle bracket ones have Lisp-like evaluation semantics.
So, in the terminology of "Build your own Lisp", (1 2 3) is effectively a Q-expression in MDL; MDL is one example of prior art for this.