Constant UNBOUNDED 

pub const UNBOUNDED: usize = usize::MAX; // 18_446_744_073_709_551_615usize

The length limit for a string whose property table gives no maximum.

A handful of OCPI properties are typed string with no (N): TaxAmount.name and TaxAmount.account_number, for example. OcpiText is the type for those: it enforces the character set and nothing else.