Hi Stefan, On 18.11.2011 01:23, Stefan Pendl wrote: > So I will have to test once more, since I thought I encountered this situation > and the file passed validation with a missing value attribute for a version > check of an uninstall check. You are right about uninstall checks. The XSD allows you to specify a type="uninstall" check without a "value" attribute. The attribute is marked to be optionsl. In fact this is correct since uninstall "exists" checks only need a "path" attribute but no value. Only uninstall version comparison require a "value" attribute. This is also documented in the XSD documentation of "value". I am currently unaware that XSD would allow to specify whether an attribute is required or optional depending on the value of another attribute. At least unless using XSLT. An option might be to specify a new type like "checkUninstallVersion" which is again derived from checks and requires the value. br, Rainer |