Dear Hend Eleraky,

Your request was discussed by the MODS Editorial Committee with the following recommendation.

If I understand you correctly you want to use the captions from DDC for subject access in MODS.  This is done by others also, as some institutions use the captions from classifications or even from the indexes to classifications as subject terms.  As a result we added the following to the Source codes document for Subject Headings and Terms,, so that these terms could be used as subjects and their source identified.  The source of the subject terms can then be identified as ddc.
"Classification schemes and subject category codes include caption terms and, frequently, index terms that identify the classes in the scheme and the category codes. Some systems use those caption and index terms as subject terms in bibliographic records. Thus the lists assigned source codes in Classification Scheme Source Codes and Subject Category Code Source Codes may also be used in the metadata elements identified below under usage, when the terms from those classification schemes and subject category codes are used as subject terms."

So you can use the following simple construct:
<subject authority="ddc">History & geography</subject>
Will this work for you?  

Regards, Sally mcCallum

Sally H. McCallum
Chief, Network Development and Standards Office
Library of Congress,  101 Independence Ave., SE
Washington, DC 20540  USA
[log in to unmask] 
Tel. 1-202-707-5119 -- Fax 1-202-707-0115

-----Original Message-----
From: Metadata Object Description Schema List [mailto:[log in to unmask]] On Behalf Of Hend Eleraky
Sent: Monday, February 18, 2013 5:28 AM
To: [log in to unmask]
Subject: [MODS] Classification alternatives

Dear All,
I need to ask about something. I need to show the dewey decimal classification in mods as categories.
 For example  : <Classification type "ddc ">History & geography <Classification> in mods schema it's stated that we put the call number for classification element [<classification authority="ddc" edition="21">911.62</classification>]
So i thought i may use "altRepGroup" for this issue .
For example :
<classification authority="ddc" edition="21"
<classification authority="ddc" edition="21" altRepGroup=1 >History & geography</classification>

Is it acceptable ??? Also , if i need to make sub-categories could i do the same scenario ?