Information Cards: More Subtleties

Another post in my new series (1,2) of posts related to things you never wanted to know about Information Cards:

• Why does the infocard.xsd define PositiveUnsignedInt when there is a XML standard positiveInteger already defined? Maybe I am missing a suble difference?
• Did you notice that the length of a claim's value is restricted to be less or equal than 684 in length?
  
  <xs:complexType name="ClaimValueType">
    <xs:complexContent>
     <xs:extension base="tns:BaseClaimType">
      <xs:sequence>
      <xs:element name="Value" type="tns:StringMaxLength684"/>
     </xs:sequence>
    </xs:extension>
    </xs:complexContent>
  </xs:complexType>
  I am very interested to here the story who came up with this number and why (My guess is that a Windows UI component restricts the length...). People who suggest to store whole customer profiles in claims should be aware of this restriction.
• Did you know that the username/password credential hint is limited to 64 characters in length?! This makes Pamela's invalid Information Card (I4-badidp1.crd) even more invalid.