4.8 String Handling

Columns that capture string values conforming to specified requirements foster data integrity, interoperability, and consistency, improve data analysis and reporting, and support reliable data-driven decision-making.

All columns capturing a string value, defined in the FOCUS specification, MUST follow the requirements listed below. Custom string value capturing columns SHOULD adopt the same requirements over time.

Requirements for string-capturing columns appearing in a FOCUS dataset.

• String values MUST maintain the original casing, spacing, and other relevant consistency factors as specified by providers and end-users.
• Charges to mutable entities (e.g., resource names) MUST be accurately reflected in corresponding charges incurred after the change and MUST NOT alter charges incurred before the change, preserving data integrity and auditability for all charge records.
• Immutable string values that refer to the same entity (e.g., resource identifiers, region identifiers, etc.) MUST remain consistent and unchanged across all billing periods.
• Empty strings and strings consisting solely of spaces SHOULD NOT be used in not-nullable string columns.

• When a record is provided after a change to a mutable string value and the ChargeClass is "Correction", the record MAY contain the altered value.