value

A value is the optional value of the tag. The string value can be from 1 to 256 Unicode characters in length and can't be prefixed with aws: or rds:. The string can only contain only the set of Unicode letters, digits, white-space, '', '.', ':', '/', '=', '+', '-', '@' (Java regex: "^([\\p{L}\\p{Z}\\p{N}.:/=+\\-@]*)$").