https://beam.apache.org/releases/javadoc/2.66.0/org/apache/beam/sdk/transforms/display/DisplayData.ItemSpec.html
DisplayData.ItemSpec (Apache Beam 2.66.0)
apache beam
https://learn.microsoft.com/en-us/dotnet/api/microsoft.build.framework.itaskitem.itemspec?view=msbuild-18-netcore&redirectedfrom=MSDN
ITaskItem.ItemSpec Property (Microsoft.Build.Framework) | Microsoft Learn
Gets or sets the item "specification" e.g. for disk-based items this would be the file path.
microsoft buildpropertyframeworklearn