ValueName pattern in AttributeRegistry_v1.

Hi All,



I have a query about "ValueName" value pattern defined in AttributeRegistry_v1.xml. I would like to understand why pattern is defined as "^[A-Za-z][A-Za-z0-9_]+$". We have a resource is trying to apply AttributeRegistry_v1.xml but only "ValueName" value can't meet the requirement. The value might contain white space or other special chars. Below is an example of the values.
 Please confirm and share your valuable input, thanks.





<Property Name="ValueName" Type="Edm.String">



<Annotation Term="OData.Permissions" EnumMember="OData.Permission/Read"/>



<Annotation Term="OData.Description" String="The value name of the attribute."/>



<Annotation Term="OData.LongDescription" String="The value of this property shall be a string representing the value name of the attribute. ValueName is a unique string within the list of possible values in the 'Value' array of a given attribute."/>



<Annotation Term="Validation.Pattern" String="^[A-Za-z][A-Za-z0-9_]+$"/>



</Property>





Example:

{

"ValueDisplayName": "128 Bytes",

"ValueName": "128 Bytes"

},

{

"ValueDisplayName": "Keep Link ON",

"ValueName": "Keep Link ON"

},










BR,

Caffrey