Crucible is able to detect file type by file name extension and apply the correct highlighting rules.

Often it is convenient to keep an executable script under source control, and do reviews against it. An executable script typically has no file name extension; its file type is identified by the

See also: https://community.atlassian.com/t5/Fisheye-Crucible-questions/Detect-language-for-syntax-highlighting-based-on-shebang-in/qaq-p/430065