Comment by chrismorgan

.gitignore is not a standard: it’s a format used by one tool. A few other tools piggy-back on it (e.g. ripgrep ignores paths matching in .gitignore, .hgignore, &c. by default), not infrequently to confusion.

CONTRIBUTING.md is not a standard: it’s a convention pushed by one platform, used by some projects (but many more will not write down such information, or put it in a README file, or put it in some other documentation).

LICENSE is definitely not a standard: it’s one of a wide variety of names people use to hold licensing information, which some tools will be able to detect. I just looked through my /usr/share/licenses, of 1135 files, only 300 are named LICENSE—it’s the most popular single name, sure, with COPYING next at 182, but it’s still definitely a minority, though in certain ecosystems it may be more popular. Any license-detection tooling will be scanning for a lot more file names. “LICENSE” is a very weak convention, compared with the others.