In an ODD, when using <valItem> elements to define a list of allowed values for a given attribute, @ident is used to contain an allowed value, e.g. <valItem ident="value1"/>. @ident is of type data.name (i.e., an XML name).
The problem with this is that it is perfectly possible one might be dealing with an attribute that requires a data.pointer, so one might wish to write
<valList mode="replace" type="closed">
or you might want to allow other types of attribute values, such as:
<valItem ident="London and Paris"/>
which are all invalid in the current schema.
Whilst I believe every other element within the tagdocs module that uses @ident from att.identified requires an XML name, this is not the case with <valItem>, so might I suggest that this element has a separate implementation of @ident of type "text".