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.