Character repertoire checking for SML cells

[MURATA Makoto (FAMILY Given)]

I am wondering how we should attach CREPDL schemas to SML cells.

Option A)

1) Introduce an attribute (say @c) to elements <c> in SML.
    This attribute is an ignorable attribute.
2) Introduce a new OPC part.  The direct child elements of the 
    root element are CREPL schemas, as specified in 19757-7.
3) The @c attrribute specify which of the direct child elements 
    is used for the cell in question.

Option B)

1 and 3) are the same as in A).
2) Introduce a new OPC part.  Each direct child element of the root
    element references a CREPDL schema, which is another OPC part.

Which do you think is better?  Do we have to introduce relationship
element (in sheetx.xml.rels) for each sheetx.xml?

Regards,
Makoto