Simply making a pdf available on a website is no Open Access.
Institutional and thematic Open Access Repositories, destined for 'Green' Open Access 
repositories, such as Orfeo, comply with 3 internationally recognized standards: OAI-PMH compatibility, Dublin Core Metadata description and the Creative Commons CC BY user licence. Orfeo is a DSpace system .
It is a centralised Open Access repository for 14 organisations:
