Probably it is closer to say that "write only" implies that the person making the claim only understands part of the language, not that it's entirely unknown to him/her. Case in point - I can fluently order food in Spanish, but I do not actually speak Spanish. Take me out of a restaurant setting, and I have serious problems understanding what people are saying (unless they happen to be talking about enchiladas).

In Perl (or any other rich programming language), there are many ways of getting a task done. It is entirely possible to be able to write a decent Perl program, but not to be able to clearly grasp what someone else has written - even if it happens to do the same task.

Your comment about a Turing machine program was excellent, and seems to offer a rebuttal to the complaint about Perl being "write-only". The original post discussed the criticism that Perl is too *rich*, that programmers had too many ways of saying things, making it difficult for other programmers to understand what they wrote. While there might be some truth to that idea, your idea is clearly another answer. A language that is feature *poor* is also hard to understand - perhaps even more difficult than one that is rich.

I think this probably says that we don't really have a good definition for what "write-only" means, in the context of a programming language. Whatever it means, though, I don't consider the fact that Perl is rich, to be a defect. I like being able to do things in a variety of ways, even if it does make it more difficult for me to follow what someone else has done. That difficulty is a reflection of my own shortcomings, not of the language. I simply haven't learned what X means, yet. One great benefit of Perl Monks is seeing so many different, often (but not always) brilliant ways of getting something done. It forces me to stop, puzzle out why the Monk chose that idiom, and to decide whether this way is better than whatever I came up with.