Charles W. Bailey stellte am 5/13/05 in DigitalKoans eine Taxonomie der Zugänglichkeit von Zeitschriften vor: The Spectrum of E-Journal Access Policies: Open to Restricted Access. Danach folgte noch Is the Access Spectrum a Red Herring or Are Green and Gold Too Black and White? als Erläuterung auf Stevan Harnad’s Einwände A Plea for Chrononomic Parsimony and Focus On What Really Matters.
- Open Access journals (OA, green). Example: Biomedical Digital Libraries.
- Free Access journals (FA, cyan). Example: The Public-Access Computer Systems Review.
- Embargoed Access journals (EA, yellow). Example: Learned Publishing.
- Partial Access journals (PA, orange). Example: College & Research Libraries.
- Restricted Access journals (RA, red). Example: Library Administration and Management.