ids.XSD - Invalid xs:attributeGroup ref="xs:occurs" in applicabilityType

[spaih]

Background:
Started building a Plugin for IDS-Data-Exchange and run into technical problems, as the current IDS.xsd is not fit for automatic validation in standard .XSD parser, due to technical mistakes. Did not find any corresponding issue here. Please point me when I’m wrong (1 of 2). New to the party. Programming civil engineer and CAD dev. Hi!
Description:
The ids:applicabilityType definition in the XSD contains an xs:attributeGroup ref="xs:occurs" element directly under xs:complexType.
Problem:
According to the XML Schema Part 1: Structures Second Edition, Section 3.4.2, xs:attributeGroup references are not permitted directly as children of xs:complexType. The minOccurs and maxOccurs attributes (which xs:occurs bundles) are applicable to element declarations (xs:element) or model group particles (xs:sequence, xs:choice, xs:all), not to the complex type definition itself. This construct makes the schema invalid.
Impact:
The schema fails validation with standard XSD processors.
Suggested Fix:
I can suggest nothing but removal and maybe add a choice between the 3 possible states, as suggested in the developer documenation "required, optional, prohibited" directly instead of that dirty and technial wrong hack!

[spaih]

Dirty Fix:

<xs:attributeGroup ref="xs:occurs"/>
into

		<xs:attribute name="minOccurs" type="xs:string" use="optional"/>
		<xs:attribute name="maxOccurs" type="xs:string" use="optional"/>

This makes it technically interpretable, and validates all existing demo file successfully.

however that is totally misleading, as these are technical attributes not to use for content. As i wrote in the suggestion i would replace this with an optional enum, 'required'optional'prohibited'