Change text from
The enumeration type MUST assign an value to the `edm:UnderlyingType` attribute.
to
The enumeration type MUST assign a value of Edm.Byte, Edm.SByte, Edm.Int16, Edm.Int32, or Edm.Int64 to the edm:UnderlyingType attribute.
Applied in https://www.oasis-open.org/apps/org/workgroup/odata/download.php/46788/odata-csdl-v1.0-wd01-2012-08-28-RH.doc
Accepted: https://www.oasis-open.org/committees/download.php/46979/odata_meeting-5_on-20120830_minutes.html