Readonly_OCR whitelist. Empty string means no restriction. Only characters that are present in the allowedCharacters string will be accepted. For example, if allowedCharacters is set to "ab", the result may only contain characters 'a' and 'b'.
Default is ""
Whether the pattern should match the whole string or just a substring.
Default is false.
Pattern to match. It can be a simple pattern or a regular expression.
Grammar of pattern matching.
Default is WILDCARD.
Pattern content validator.