MEDLINE Baseline Repository
                           Frequency Counts README File
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Chemical Files (RN terms):

   -- Format of files:
       Frequency count overall in MEDLINE
       Registry Number for the Chemical
       Chemical name

   -- Chemical_freq_alpha -- Ordered by Chemical name
   -- Chemical_freq_count -- Ordered by Frequency counts (high->low)



Main Heading (MH) Files (MH terms):

   -- Format of files:
       Frequency count overall in MEDLINE
       Frequency count when starred (major) item
       MeSH Heading

   -- MH_freq_alpha -- Ordered by MeSH Headings
   -- MH_freq_count -- Ordered by Overall Frequency counts (high->low)
   -- MH_major_freq_count - Ordered by Starred Frequency counts (high->low)



SubHeading (SH) Files (qualifier terms):

   -- Format of files:
       Frequency count overall in MEDLINE
       Frequency count when starred (major) item
       SubHeading or Qualifier name

   -- SH_freq_alpha -- Ordered by Subheadings/qualifier
   -- SH_freq_count -- Ordered by Overall Frequency counts (high->low)
   -- SH_major_freq_count - Ordered by Starred Frequency counts (high->low)



Main Heading/SubHeading (MH_SH) Combination Files 
                                              (MH/qualifier combination terms):

   -- Format of files:
       Frequency count overall in MEDLINE
       Frequency count when starred (major) item
       MH/SubHeading name combination

   -- MH_SH_freq_alpha -- Ordered by MH/SH
   -- MH_SH_freq_count -- Ordered by Overall Frequency counts (high->low)
   -- MH_SH_major_freq_count - Ordered by Starred Frequency counts (high->low)

   ** Special Note:

      This counts all variants of the MH/SH combinations, applying the starred
      count only to combinations that include the starred term - for example:

      If we have an entry like the following in a citation:
         MH  - Obesity/*complications/etiology

      We include the following entries in this table:

         Obesity/*complications
         Obesity/etiology

         1|1|Obesity/complications
         1|0|Obesity/etiology