3.1.3 The Mapping between XML Representations and Components
"above and beyond those implicit in the Schema for Schema Documents"
implicit is a very strange choice here.  change to expressed.

3.1.4 White Space
from: "necessary to ensure a consistent ·validation· semantics for simple types"
to:   "necessary to ensure   consistent ·validation· semantics for simple types"

3.2 Attribute Declarations
"The {name} property must match the local part of the names of attributes being ·validated·.
The value of the attribute must conform to the supplied {type definition}.
A ·non-absent· value of the {target namespace} property provides for ·validation· of namespace-qualified attribute information items ("
switches back and forth between singular and plural.

3.2 Attribute Declarations
"The default when no simple type definition is referenced..."
seems to belong with previous paragraph, remove preceding paragraph break

3.2.3 Constraints on XML ...item 4
from: "4 type and     <simpleType>               
     must not"
to:   "4 type and the <simpleType> child element (i.e. an anonymous in-line type def) must not"

3.2.3 Constraints on XML ...item 6
from: "not present"
to:   "absent"

3.2.3 Constraints on XML ...item 6.3.2
from: "corresponding to              <complexType>. B's {attribute uses}"
to:   "corresponding to its ancestor <complexType>. B's {attribute uses}"
(if this makes sense... it was hard to mentally de-ref <complexType>)

3.2.4 Attribute Declaration Validation Rules, Validation Rule: Schema-Validity Assessment (Attribute)
from: "For attribute                 s, there is no difference"
to:   "For attribute information items, there is no difference"

Schema Component Constraint: xsi: Not Allowed
from: "Note: It is not illegal for Attribute Uses that"
to:   "Note: It is       legal for Attribute Uses that"