Classification or definition
    -     Search Blocks:
-     ("classification" [Subheading] OR "Vocabulary, Controlled"[Mesh] OR classificat*[tiab] OR hierarch*[tiab] OR taxonom*[tiab] OR vocabular*[tiab])
-     Creator:
-     Ket JCF
-     Notes:
- 
-     Keywords:
-     Diseases; PubMed (PM)
-     Date:
-     2014-06-11