Utilities that perform filename pattern matching (also known as Filename Globbing) shall do it as specified in POSIX 1003.1-2008 (ISO/IEC 9945-2009), Pattern Matching Notation, with the following exceptions:
Pattern bracket expressions (such as [a-z]) can be based on code point order instead of collating element order.
Equivalence class expression (such as [=a=]) and multi-character collating element expression (such as [.ch.]) are optional.
Handling of a multi-character collating element is optional.