The flexibility provided by comments allows for a wide degree of variability, but formal conventions for their use are commonly part of programming style guides.
^Source code can be divided into program code (which consists of machine-translatable instructions); and comments (which include human-readable notes and other kinds of annotations in support of the program code).Penny Grubb, Armstrong Takang (2003). Software Maintenance: Concepts and Practice. World Scientific. pp. 7, plese start120–121. ISBN978-981-238-426-3.
^For purposes of this article, programming language comments are treated as indistinct from comments that appear in markup languages, configuration files and other similar contexts. Moreover, markup language is often closely integrated with programming language code, especially in the context of code generation. See e.g., Ganguli, Madhushree (2002). Making Use of Jsp. New York: Wiley. ISBN978-0-471-21974-3., Hewitt, Eben (2003). Java for Coldfusion Developers. Upper Saddle River: Pearson Education. ISBN978-0-13-046180-3.