Trailing Spaces Present in Enumerated Values for Some HIMSA Data Standards
Apr 26, 2025
It has been discovered that few of more recent data standard schema files have included some enumerated values with a trailing space, which may cause some issues with applications reading data saved by other software, This issue has existed since the initial release of Audiogram format 502 in 2016. The impacted standards are:
Audiogram Format, format 502
Admittance Format, format 501
Scan Meta Data Standard, format 500
High-Level Description using the Audiogram 502 standard as an example
When standards are created, HIMSA uses XML SPY as a tool to help create and document the XSD files
In the picture below, the red arrow points to “none,” but the value is really recorded as “none “—note the trailing space after 'e'. This is more obvious in the text view of the XSD file.
Q: Is it wrong to have a trailing space?
A: It is certainly not desirable and was never the intention. The working theory on the cause of this is that the values were copied and pasted into XML SPY, and when copied, an extra space was kept and never noticed.
Q: Is saving data without the trailing space legal?
A: After extensive investigations, HIMSA has concluded that this is legal for the following reasons:
Noah always validates all data following a public format before allowing it to be saved as an action into Noah. If an leading or trailing space is present the validation routines that Noah uses will already remove the spaces during the validation process but not remove actual data saved in the Noah action.
HIMSA can use XML spy to take the same file and also use the validation tools within XML spy to validate it. The file does pass validation. It is also interesting to note that the XML file can be manually updated to include the value “ none “ (with both a leading and trailing space), and this will also pass validation.
Through HIMSA’s investigations, the WC3 resource found on the requirement of file normalization, is important to understand.
Section 3.3.3 states “If the attribute type is not CDATA, then the XML processor MUST further process the normalized attribute value by discarding any leading and trailing space (#x20) characters, and by replacing sequences of space (#x20) characters by a single space (#x20) character.”
HIMSA understands that both .NET and XML SPY normalize the data, which explains the findings above.
HIMSA regrets the presence of this trailing space and has taken steps to help ensure that it will not occur in future data standards or revisions.
Q: Will HIMSA fix the schema file (XSD) for the Audiogram format 502 standard?
A: No, as the standard was released in 2016 HIMSA would fear that any changes to the schema may cause unexpected issues for other software.