XML and combinatorial chemistry

Dear CCL,
 Does CML or any other chemical XML application support combinatorial
 chemistry? Specifically, I have in mind Markush or generic structures with
 lists of R groups. Is specific support for Markush structures necessary or
 useful, or is there a way to do it with existing CML elements? The CML FAQ
 (http://www.xml-cml.org/faq/index.html) notes that
 "Heteromers" e.g.
 modified proteins, are difficult to represent, which suggests a Markush may
 be as well. Thanks in advance.
 Regards, Eric
 Eric Martin
 Chiron Corp, LSC 4.250
 4560 Horton St.
 Emeryville, CA 94608
 FAX 923-2010
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