Our validating XML parser adds attributes with fixed values from MODS-Schema to imported MODS XML,
e.g. <mods:typeOfResource collection="yes" manuscript="yes" usage="primary">
This is correct behaviour, (W3C definition for fixed attributes), but makes no sense within MODS.
The attributes should be truly optional, therefore it is correct to use a restricted simple type with one value.
Until we get a solution from LoC, we will enhance our local MODS-Schema.