I was advised by an experienced club member that law is not language. Therefore, it can't be discussed on this website.
The question is rather inelegantly worded, and it would be difficult to answer it exactly as formulated, but I take it that what the OP really wants to know is whether the questions about the features of English language that are peculiar to legal contexts are within the scope of this site, and, if not, why not. The OP earlier asked a substantive question about whether the meaning of a legal prohibition of ‘using a mobile phone’ while driving can cover one’s merely holding the phone without making a call. That question received several downvotes and critical comments, which prompted the OP to ask this meta-question. (The substantive question has, since then, been closed and deleted.)
Many terms whose meaning in everyday language is vague are explicitly given a precise meaning for legal purposes. A statute may thus have a provision that says something like ‘In this statute, ‘using a mobile phone’ means . . . .’ If that's what the statute says, then that's what the phrase means in that context, notwithstanding the fact that its meaning in other contexts may be broader or narrower. If there is no such provision within the statute, chances are that the courts of the relevant jurisdiction have previously considered the question of whether the prohibition of using a mobile phone covers holding it without making a call, and that they have decided the matter one way or another. That decision then constitutes the precedent that will govern the future court decisions in the same jurisdiction. If there is no such precedent, and a court needs to face the question for the first time, the court will probably look at how similar phrases in similar contexts have been interpreted by the courts before. Somebody who wants to know about all this has to engage in legal research, or hire a lawyer to do the research, and that research has to be jurisdiction-specific. No amount of general knowledge about English language can tell us whether a person can be justifiably punished for holding a phone without making a call, under a statute that prohibits using a mobile phone. That's why such questions are outside the scope of this site.
That, of course, does not mean that all law-related question are outside the scope of this site. The boundary between the language of the law and everyday language is not sharp. Legal terminology, for example, often finds its way into news reports and political debates. Because the language of the law changes more slowly than colloquial language, it can sometimes provide insights into the history of the language. The questions that explore the language of the law in such interaction with the language used in other contexts have always been welcome on this site.
The questions about the highly technical aspects of legal terminology are, however, likely to get better responses on the Law Stack Exchange. It should also be borne in mind that no Stack Exchange site can provide legal advice; some law-related questions are closed because they appear to amount to requests for legal advice.