These patterns do not literally match many system names, but are still generally recognized to refer to any UNIX system, descendant, or work-alike, even those with completely dissimilar names such as Darwin/ macOS, illumos/ Solaris or FreeBSD. Some add a wildcard character to the name to make an abbreviation like 'Un*x' or '*nix', since Unix-like systems often have Unix-like names such as AIX, A/UX, HP-UX, IRIX, Linux, Minix, Ultrix, Xenix, and XNU. Other parties frequently treat 'Unix' as a genericized trademark.
Their guidelines require 'UNIX' to be presented in uppercase or otherwise distinguished from the surrounding text, strongly encourage using it as a branding adjective for a generic word such as 'system', and discourage its use in hyphenated phrases. They do not approve of the construction 'Unix-like', and consider it a misuse of their trademark. The Open Group owns the UNIX trademark and administers the Single UNIX Specification, with the 'UNIX' name being used as a certification mark.
