Duplicate test detected.
#2506 Compile-time warning
Duplicate test detected.
Additional Information
Entity test X already appears.
where X is an entity test, such as GENERAL, PARAMETER, CDATA-ENTITY,
etc.
or
Notation test X already appears.
where X is a notation test, such as SYSTEM, PUBLIC, or IN-LIBRARY.
or
Declared type X has already been specified.
where X is one of the declared types an element attribute can take,
or the keyword 'GROUP'.
or
Attribute test X already appears.