In computer programming, a naming convention is a set of rules for choosing the character sequence to be used for identifiers which denote variables, types, functions, and other entities in source code and documentation.
There are several naming conventions in different languages.
But is there any pattern/conventions followed by companies to name keywords and other terms used in programming environment ?
Your question is kind of broad in the sense that is about "terms used in programming environment". First I'm going to reduce the answer to "language keywords":
No there isn't a general pattern for programming language keywords, it depends on each language designer preference and the language "inheritance", ie: Java/JavaScript share some of the keywords inherited from C/C++.
Most of the time the reason to choose a keyword format over the other has to do with the handling of the language grammar to create the parser. For example if you allow keywords that starts with "-", then you need to be careful to not generate ambiguity with expressions like: - value, -value or valueA - value B.
Some languages prefer to reduce keywords to the minimum. For example Lisp and Smalltalk doesn't have many keywords, and even constructs for "if" or loops are handled as function/method calls.
And for the broad sense of "terms used in programming environment ", it the depends a lot on the background of the language designers (rather than in the company that backs them), for example:
