- Case-insensitive matching: https://blogs.oracle.com/xuemingshen/entry/case_insensitive_matching_in_java
- (?i) means: for ASCII case-insensitive matching:
- "XYZxyz".matches("(?i)[a-z]+")
- (?iu) means: for Unicode case-folding
- (?i) means: for ASCII case-insensitive matching:
- s
- s
- s
- s
- ss