In June 2003, the PMC Advisory Committee affirmed the policy that journals joining PMC must make the full text of their deposited content viewable in PMC, and endorsed the following participation guidelines:

• Journals are encouraged to deposit the complete contents of each issue, not just research papers or other selected parts, in the PMC archive.
  
  
• Journals are encouraged to provide this content to PMC as close to publication as possible, regardless of when they allow it to be publicly accessible, as this makes it easier for them to correct errors detected in the journal’s files during PMC’s data review process.
  
  
• Journals are encouraged to allow their primary research articles to be viewable in PMC as early as possible but generally less than one year from publication date.
  
  
• Journals are encouraged to allow all other journal content (e.g. letters, reviews, etc.) to be viewable in PMC as early as possible but generally less than three years from publication date.